Background: The Surgeon General has called for an expansion of school-based extracurricular sports programs to address the obesity epidemic. However, little is known about the availability of and participation in high school extracurricular sports and how participation in these sports is related to high-risk behaviors. Methods: We surveyed Los Angeles County public high schools in 2002 to determine the number of extracurricular sports programs offered and the percentage of students participating in those programs. We used community data on rates of arrests, births, and sexually transmitted diseases (STDs) among youth to examine associations between risk behaviors and participation in sports programs. Results: The average school offered 14 sports programs, and the average participation rate was 39% for boys and 30% for girls. Smaller schools and schools with higher percentages of disadvantaged students offered fewer programs. The average school offering 13 or fewer programs had 14% of its students participating, while the average school offering 16 or more programs had 31% of its students participating in sports. Controlling for area-level demographics, juvenile arrest rates and teen birth rates, but not STD rates, were lower in areas where schools offered more extracurricular sports. Conclusions: Opportunities for participation in high school extracurricular sports are limited. Future studies should test whether increased opportunities will increase physical activity and impact the increasing overweight problem in youths.