Introduction: African American (AA) high school-age girls are more likely to have had sex before age 13 years and have higher rates of all sexually transmitted infections. Cognition and religion/spirituality are associated with adolescent sexuality, therefore, the purpose of this study was to identify cognitive and religious substrates of AA girls’ risky sexual behaviors. Method: A descriptive study was conducted with 65 AA girls aged 15 to 20 years using computerized questionnaires and cognitive function tasks. Results: Average age was 17.8 ± 1.9 years and average sexual initiation age was 15.5 ± 2.6 years. Overall, 57.6% reported a history of vaginal sex. Girls who reported low/moderate religious importance were significantly younger at vaginal sex initiation than girls for whom religion was very/extremely important. Girls who attended church infrequently reported significantly more sexual partners. Implications: Health care providers can use these findings to deliver culturally congruent health care by assessing and addressing these psychosocial factors in this population.