Objectives The purpose of this study was to examine if youth soccer players' perceived relationships with parents and peers in soccer, and the moderating associations among these social relationship variables, predict soccer continuation over and above motivation-related variables. Design This study used a prospective design by assessing youth soccer athletes' social relationships and motivational outcomes during one season and tracking the athletes' soccer continuation behavior one year later. Methods Continuation behavior of travel soccer athletes ( N = 148), ages 10–14 years ( M = 11.7, SD = 1.0), was assessed one year after completing a questionnaire containing soccer-contextualized measures of perceived parent relationship quality, perceived friendship quality, perceived peer acceptance, perceived competence, enjoyment, stress, and self-determined motivation. Results Logistic regression analyses showed that greater perceived competence, more positive friendship quality, and the combination of mother relationship quality and peer relationships predict soccer continuation on the same team. Conclusions The findings highlight the importance of close social relationships, and the combination of parent and peer relationships in particular, to sport continuation behavior.