Family health history about cancer is an important prevention and health promotion tool. Yet, few studies have identified family context factors that promote such discussions. We explored relations among family context (cohesion, flexibility, and openness), self-efficacy, and cancer communication (gathering family history, sharing cancer risk information, and frequency) in a diverse group of women enrolled in a randomized control trial. Baseline survey data for 472 women were analyzed. Average age was 34 years, 59% identified as Black, 31% graduated high school, and 75% reported a family history of any cancer. Results showed that greater family cohesion and flexibility were related to higher communication frequency and sharing cancer information. Women who reported greater self-efficacy were more likely to have gathered family history, shared cancer risk information, and communicated more frequently with relatives. Openness was not associated with communication but was related to greater family cohesion and flexibility. Adjusting for demographic variables, self-efficacy and family cohesion significantly predicted communication frequency. Women with higher self-efficacy were also more likely to have gathered family health history about cancer and shared cancer risk information. Future research may benefit from considering family organization and self-efficacy when developing psychosocial theories that, in turn, inform cancer prevention interventions.