During adolescence, the number of cross-sex friends increases dramatically. This study focused on correlates of adolescents' cross-sex friendship satisfaction. Three hundred and twenty Hong Kong secondary four (10th grade) students were asked to rate their best cross-sex friends on the Friendship Satisfaction Scale (Tsuzuki & Matsui, 2000). Masculinity, school type, total number of cross-sex friends, and both generic and unique friendship motives significantly explained 48.9% of adolescents' satisfaction with their cross-sex friends. Thus, variables ranging from individual traits to opportunity structures can all be useful in understanding adolescents' cross-sex friendship development.