The current research examined children’s observed compliance in a family clean-up paradigm and parents’ reports of coparenting to predict young children’s conscience (e.g., affective discomfort and moral regulation) in a sample of 58 families with two parents and at least two children. Results demonstrated relations between parent reports of children’s conscience development and observer-rated compliance in a family clean-up session, in addition to significant correlations between coparenting and conscience development. There were more significant results for younger, 2-year-old siblings than older siblings which may reflect the importance of the period between 2 and 3 for the emergence of conscience. Multiple regressions revealed that younger siblings’ age, observed compliance/noncompliance, and parent reports of coparenting were significant in predicting parents’ reports of affective discomfort and moral regulation. Findings underscore the importance of continuing research on whole-family dynamics when studying young children’s early conscience and moral regulation.