It is a household notion that secrecy is bad while sharing is good. But what about shared secrets? The present research adopts a functional analysis of sharing secrets, arguing that it should negate harmful consequences generally associated with secrecy and serves important interpersonal functions in adolescence. A survey study among 790 Dutch adolescents showed that, in line with hypotheses, shared secrets (1) were kept by more adolescents than private secrets, (2) were not linked to maladjustment and (3) were linked to higher interpersonal functioning. Whereas private secrecy was associated with increased delinquency, physical complaints, depressive mood, loneliness, and with lower quality relationships, shared secrecy was associated only with more interpersonal competence. Moreover, sharing a secret was specifically linked to a higher quality relationship with the confidant, and sharing with parents was linked with less delinquency, whereas sharing with a best friend was linked with less loneliness and more interpersonal competence. (Contains 3 tables.)