This study examined the influence of family structure on the outcomes of a sex education program in Miami, Florida. Using an experimental design, data collection occurred at pretest, 3-month, and 6-month follow-up with a sample of teenagers from high schools with a large majority of minority youth, assigned into treatment (n = 549) and control (n = 424) groups. Results indicated family structure had no influence on predicting teen sexual activity at pretest or at 3- or 6-month follow-up. Additional research using experimental designs is needed to assess the influence of family structure on other areas of adolescent development.