Background: This study examines the prevalence of vaginal, oral, and anal intercourse among a population of urban, public middle school students, the characteristics of early sexual initiators, and the sequence of sexual initiation. Such data are limited for early adolescents. Methods: A total of 1279 seventh-grade students (57.3% female, 43.6% black, and 41.8% Hispanic), mean age 12.5 years (SD = 0.63) from 10 middle schools in a large southeastern US public school district completed a cross-sectional survey using audio computer-assisted self-interviews. Main outcomes included lifetime and past 3-months' experience of vaginal, oral, and anal sex; condom use; age of initiation; and number of lifetime partners. Results: Overall, 12.0% of students had engaged in vaginal sex, 7.9% in oral sex, and 6.5% in anal sex. Among students who had initiated intercourse, approximately two thirds were currently sexually active and one quarter reported greater than or equal to 4 lifetime partners. Six percent had engaged in 1 type of intercourse, 4% in 2 types of intercourse, and 4% in all 3 types of intercourse; vaginal sex was typically initiated at an earlier or at the same age as other types of intercourse. Only 2% had engaged in oral sex without engaging in vaginal sex. Although black students were significantly more likely to have initiated sex compared to other racial/ethnic groups, Hispanic students who had initiated each type of intercourse were more likely to be currently sexually active and to have engaged in recent unprotected sex. Conclusions: A small percentage of early adolescents are engaging in multiple sexual behaviors. These findings have implications for early adolescent school-based sexual health education. (Contains 1 figure and 3 tables.)