Social acceptance and peer and romantic relationship self-efficacy were examined as salient factors related to social development among emerging adult (ages 18 to 25) survivors of pediatric cancers. Using a cross-sectional, within-groups methodology, relationships between cancer treatment intensity and peer and romantic relationship self-efficacy and social acceptance were assessed. Perceived health vulnerability, situational coping style, parent and peer attachment, and perceived physical attractiveness were explored as moderators of peer and romantic relationship self-efficacy and social acceptance. Additionally, social acceptance was examined within a cancer stereotyping framework. Fifty-two emerging adult survivors of pediatric cancers (54% male; mean (M) age = 21.38 years, standard deviation (SD) age = 3.11 years) completed self-report questionnaires. Participants were diagnosed between ages 5 and 19 (Mage = 12.59 years, SDage = 4.57 years) and were at least six months post-active treatment (Mtime = 7.32 years, SDtime = 4.46 years). Simultaneous regression analyses indicated that health vulnerability, coping style, parent and peer attachment, and physical attractiveness together accounted for a significant amount of variance in peer and romantic relationship self-efficacy and self-perceived social acceptance. There were significant main effects of perceptions of physical attractiveness and peer attachment on peer relationship self-efficacy and self-perceived social acceptance. There was also a main effect of perceived physical attractiveness on romantic relationship self-efficacy. However, treatment intensity was not significantly related to peer or romantic relationship self-efficacy or social acceptance. Furthermore, there were no significant moderating effects of health vulnerability, coping, parent or peer attachment, or physical attractiveness on the relationship between treatment intensity and peer or romantic relationship self-efficacy or social acceptance. In terms of social acceptance, participants believed that others’ viewed them as more socially accepted than they viewed themselves. Participants also rated a hypothetical peer with cancer as less socially accepted than healthy peers. Results suggest greater perceived physical attractiveness and stronger attachment to peers may be strongly related to greater relationship confidence and feelings of being socially accepted. Survivors may also hold stereotyped views of their own level of social acceptance and the social acceptability of peers diagnosed with cancer. Future research and interventions implications are considered.