LACSEF: Stand Out At The Los Angeles County Science Fair

The Los Angeles County Science & Engineering Fair (LACSEF) brings together middle and high school students from across the county to showcase their research, compete with peers, and open new pathways of discovery.

It's a competition and celebration of scientific curiosity, and participating offers access to thousands of dollars in prizes and scholarships. This guide walks you through who's eligible, how to enter, and how to succeed.

Understanding LACSEF

LACSEF spans a diverse range of categories, from engineering and the biological and physical sciences to behavioral sciences, mathematics, and computer science, so students can explore and showcase their talents in almost any field. Students present their projects through detailed display boards and oral presentations, and a panel of judges, experts across scientific disciplines, evaluates each project's methodology, results, conclusions, and presentation.

LACSEF sits within California's broader science fair pipeline: strong projects here can advance toward the California Science & Engineering Fair, the state's ISEF-affiliated fair, and ultimately toward ISEF itself. Our guide to winning the California Science & Engineering Fair maps out that next level.

How to Succeed at LACSEF

Winning at LACSEF takes a blend of scientific rigor and strong presentation. A few strategies that make the difference:

Start Early

Give yourself enough time to collect data, analyze it, and refine your project, and if your work needs SRC pre-approval, factor that timeline in too. Rushed projects show.

Choose an Original Topic

Come up with a project idea that fits your strengths, interests, and aim for a fresh research question.

Read the Judging Criteria

Learn exactly what LACSEF judges reward: thoroughness, creativity, relevance, and clear presentation, and build your project against those standards.

Show Real-World Impact

Explain how your research could actually be used and who it could help. Relevance and impact are two things judges consistently value most.

Keep it Doable

Plan a project you can realistically complete with your time and resources, follow the scientific method or engineering design process closely, and observe all safety and approval rules throughout.

Nail the Presentation

Build a clear, visually strong display board that explains your methods, findings, and their significance, then rehearse until you can present confidently and persuasively.

To work with and get personalized advice from a science fair winner to prepare for the judges' Q&A the way top competitors do, reach out to ScienceFair.

Rules, Eligibility, and Categories at LACSEF

Every fair has different rules and regulations, so make sure to read the LACSEF rules carefully.

Who's Eligible for Los Angeles County Science & Engineering Fair

Eligibility for LACSEF is based on enrollment in a Los Angeles County school in grades 6–12, regardless of your state of residency. That includes public, charter, private, and parochial schools, as well as California state-approved homeschool or virtual school programs. Because LACSEF doesn't directly oversee student projects, there are specific participation rules built around school oversight, and the right path depends on your situation.

If you attend a public or private school, your first step is to find out whether your school already participates in LACSEF. If so, you'll need to take part through your school, coordinating with a teacher or administrator who supports your participation. If your school participates, that's your only route in.

If your school doesn't support participation, you have two alternatives: a parent or guardian can serve as your site coordinator (with an authorization letter on school letterhead from the principal or district superintendent, submitted to the LACSEF President), or you can participate through a qualified non-profit or municipal education organization, like a museum or an extracurricular science program, that agrees to provide oversight. Homeschool and virtual-school students participate based on their town of residence, with a program representative providing written oversight.

One rule worth noting early: aside from a school or district competition affiliated with LACSEF that promotes students to it, you can't participate in other outside science fairs. Every project must also go through LACSEF's full approval process and timeline, with all forms complete.

How to Enter

Entering LACSEF follows a clear sequence.

First comes school enrollment, your school (or approved alternative site coordinator) registers to participate. Next is student project registration through the LACSEF portal. Then, crucially, certain projects require pre-approval before you begin experimenting.

That pre-approval step matters, because some projects must be reviewed by the Scientific Review Committee (SRC) before any experimentation starts. Projects that need prior approval include anything involving human participants, vertebrate animals or higher-functioning invertebrates, or potentially hazardous materials.

In fact, some categories of research must be conducted in an appropriate lab and may never be done at home, including work with microorganisms (bacteria, viruses, fungi, yeast, algae, and similar), recombinant DNA technologies, human or animal tissues, cell lines, or blood products, and hazardous chemicals or devices. If your project touches any of these areas, build the approval timeline into your plan from the very start, since starting experimentation before approval can disqualify your work.

Categories at LACSEF

LACSEF organizes projects into two divisions, Juniors (grades 6–8) and Seniors (grades 9–12), each judged within the same set of categories. Choosing the right one matters, since it shapes how your project is judged, and LACSEF may move a project to a more fitting category or split and combine categories to keep them balanced. The 2026 categories are:

• Animal Biology: life cycles, growth, morphology, pathology, ecology, genetics, and cellular or tissue-level studies of animals, including humans.

• Animal Physiology: how organs and organ systems function in animals, including circulation, respiration, digestion, and temperature regulation.

• Applied Computational Science: using computational methods like simulations and machine learning to model, analyze, or solve problems in other scientific or engineering fields.

• Behavioral and Social Sciences: attitudes, behaviors, social interactions, and societal values, including animal behavior studies focused on behavior rather than cognition.

• Biochemistry and Molecular Biology: chemical and molecular processes in living things, including proteins, nucleic acids, enzymes, and metabolic pathways.

• Chemistry: chemical properties of non-biological materials, physical properties, chemical separations, reaction kinetics, and applied subfields like electrochemistry and polymer chemistry. (Juniors split this into General and Applied Chemistry.)

• Cognitive Science: learning, memory, problem-solving, decision-making, and how information is acquired, stored, and recalled.

• Earth/Space Sciences: Earth's systems (geology, meteorology, seismology, oceanography) and the astronomical sciences (astrophysics, planetary science, observational astronomy).

• Ecology: relationships between organisms and their environments, including habitats, food webs, nutrient cycles, and biodiversity.

• Engineering (Biological and Biomedical): applying engineering and design to biology and medicine, from medical devices and diagnostics to drug delivery and genetic engineering.

• Engineering (Civil and Environmental): engineering and design for infrastructure and environmental challenges, like water purification, renewable energy, and sustainable materials.

• Engineering (Electronics and Robotics): designing or analyzing electrical circuits and robotic systems, including automation, control systems, and electronics.

• Environmental (Management): the impact of natural disasters or human activity on the environment, pollution sources and remediation, and resource conservation.

• Materials Science: the physical properties of materials, including how they respond to heat, electricity, sound, light, or force.

• Mathematics and Computer Science: fundamental studies in math and computer science, from geometry and number theory to algorithms, encryption, and information theory.

• Microbiology: the genetics, growth, ecology, and physiology of microorganisms, including virology, microbial genetics, and infectious-disease studies.

• Pharmacology: the effects of drugs or chemicals on living systems, including drug action, drug discovery, and toxicology.

• Physics: the fundamental properties of matter and energy, including motion, forces, energy, heat, light, sound, and modern physics. (Juniors split this into General; Electricity and Magnetism; and Aerodynamics and Hydrodynamics.)

• Plant Biology and Physiology: the growth, structure, function, and genetics of plants, including agriculture, horticulture, hydroponics, and plant pathology.

• Product Science: comparing and testing commercial, natural, or homemade products for effectiveness, durability, safety, or performance. (Juniors division.)

  
  

Advancing From LACSEF to the State Fair and ISEF

LACSEF's top projects can advance to the California Science & Engineering Fair, and the strongest of those can go on to represent California at the Regeneron International Science and Engineering Fair (ISEF), the world's largest pre-college science competition.

Each level has its own requirements and deadlines, so once you've competed at LACSEF, follow the specific advancement guidelines carefully, and lean on LACSEF's own state-fair prep resources, so you don't miss a step on the way up.

Equip Yourself to Win at LACSEF

Succeeding at LACSEF takes a strong, original project, rigorous research, and a confident presentation, and that's exactly what ScienceFair helps you build. Every coach on our team is a past science fair winner, and alongside our Ivy League research mentors, they'll help you refine your idea, strengthen your research, and prepare for the judges' Q&A.

Ready to make your run at the LA County Science & Engineering Fair? Schedule a call with our academic advisor.