Highlights from the study findings include: 79 percent of program participants remained in the program for 3 full years; compared to a control group, female program participants had a lower risk of being sexually active and becoming pregnant, and had a positive increase in their odds of using a condom and a hormonal method following sexual intercourse; for male program participants, no change was found in their sexual and reproductive behavior outcomes; and program participation had positive outcomes for both male and female participants regarding their receipt of good primary health care. This study examined the success of the Carrera program, an afterschool program provided by the Children's Aid Society in New York City that works to prevent teen pregnancy and improve health care access for teenagers. Participants in the study were 100 disadvantaged teens, aged 13-15, who were randomly assigned to the program through 1 of 6 city agencies. The youth were followed for 3 years to obtain information about their sexual and reproductive behavior. Data for the evaluation were obtained through annual surveys of teenage participants' characteristics and program outcomes; annual tests of knowledge of sexual topics administered by the evaluation team at the same time as the annual surveys; and monthly attendance records for participants provided by program staff. Multivariate regression analyses were used to assess the effects of program participation on the sexual and reproductive behavior of the participants. The findings indicate that the Carrera program has been successful at reducing the rate of teen pregnancy in New York City, and that male participants may benefit from entering the program at an earlier age. 4 tables and 14 references