Interventions to improve communication among family members may facilitate information flow about familial risk and preventive health behaviors. This is a secondary analysis of the effects of an interactive website intervention aimed at increasing communication frequency and agreement about health risk among melanoma families. Participants were family units, consisting of one family member with melanoma identified from a previous research study (the Case) and an additional first degree relative and a parent of a child 0-17. Family triads were randomized to receive access to the website intervention or to serve as control families. Family communication frequency and agreement about melanoma prevention behaviors and beliefs were measured at baseline and again at 1 year post randomization. Intervention participants of all three types significantly increased the frequency of communication to their first degree relatives (Parents, siblings, children; range = 14-18 percentage points; all p < .05). At baseline, approximately two-thirds of all three family members talked with at least some member of the family about cancer risk. Agreement between Cases and First Degree Relatives and between Cases and Parents increased from pre to post intervention in the intervention participants compared to the control participants (p < .05). These findings provide support for interventions to improve family communication about cancer risk.