Recent reviews suggest that religiosity is associated with the delay of adolescent coital debut (Rostosky, Wilcox, Wright, Randall, in press; Wilcox, Rostosky, Randall, Wright, 2001). Few studies, however, have examined this association using longitudinal data to test theoretically driven models. We analyzed data from 3,691 adolescents (ages 15-21), testing the hypothesis that adolescent religiosity and sex attitudes (at Wave 1) predict later coital debut (at Wave 2) and that these predictive relationships vary by gender. Findings indicated that beyond demographic factors and number of romantic partners, religiosity reduced the likelihood of coital debut for both males and females. After accounting for the effects of religiosity, anticipation of negative emotions after coital debut (sex attitude factor 1) further reduced its likelihood for females and males. Finally, adolescent girls - but not boys - who anticipated positive emotions following sexual intercourse (sex attitude factor 2) were more likely to debut. While virginity pledge status was associated with coital debut for boys and girls, more conservative beliefs about sex appeared to mediate its effect. Finally, a significant interaction between race and religiosity indicated that African American adolescent males who had either signed a virginity pledge or were more religious were significantly more likely to debut than both White non-Hispanic males and African American males who were less religious and/or who had not signed a pledge. The implications of these results for adolescent pregnancy prevention programming are discussed.