The present study developed a theoretical framework for understanding the social mechanisms underlying disclosure and its link with relationship satisfaction in a full family design. A study among 262 intact families, consisting of 2 children and 2 adults and involving 1,048 individuals, applied the social relations model. Results showed that disclosure was more important to satisfaction in horizontal relationships than vertical ones. Further, relationship-specific disclosure was more important to satisfaction than dispositional disclosure. These results have implications for the examination of relationship regulation and maintenance in non-voluntary relationships and the development of psycho-social problems in parent-child relationships.