This study examined children’s secret-keeping for a parent and its relation to trust, theory of mind, secrecy endorsement, and executive functioning (EF). Children (N = 107) between 4 and 12 years of age participated in a procedure wherein parents broke a toy and asked children to promise secrecy. Responses to open-ended and direct questions were examined. Overall, secret-keeping increased with age and promising to keep the secret was related to fewer disclosures in open-ended questioning. Children who kept the secret in direct questioning exhibited greater trust and better parental ratings of EF than children who disclosed the secret. Findings highlight the importance of both social and cognitive factors in secret-keeping development.