Little research has been done on the social contexts of adolescent sexual behaviors in sub-Saharan Africa. As part of a longitudinal cohort study (N = 1275) of teenage girls and boys in two Ghanaian towns, interviewers administered a 26-item questionnaire module intended to assess four dimensions of youth–adult relationships: monitoring, conflict, emotional support, and financial support. Confirmatory factor and traditional psychometric analyses showed the four scales to be reliable. Known-groups comparisons provided evidence of their validity. All four scales had strong bivariate associations with self-reported sexual behavior (odds ratios = 1.66, 0.74, 0.47, and 0.60 for conflict, support, monitoring, and financial support, respectively). The instrument is practical for use in sub-Saharan African settings and produces measures that are reliable, valid, and predictive of sexual behavior in youth.