Men diagnosed with early stage prostate cancer face multiple treatment options, each with distinctive side effects that have significant implications for post-treatment quality of life. Healing Choices for Men with Prostate Cancer is a multimedia educational and decision aid program. This nation-wide randomized controlled trial evaluated the impact of Healing Choices on reducing decisional conflict and distress. Eligible prostate cancer patients who called the National Cancer Institute's Cancer Information Service (CIS) were invited to participate. After a baseline interview, participants were randomized to usual personalized consultation with a CIS specialist (comparison condition) or CIS personalized consultation plus the Healing Choices program (intervention condition). The Decision Conflict Scale and Impact of Event Scale assessed decisional conflict about prostate cancer treatment and cancer-related distress, respectively. Analyses evaluated group differences at 2 months postenrollment. Hypothesized moderation of intervention effects by demographic and clinical characteristics were evaluated. The final sample consisted of N = 349 participants (intervention: n = 181; comparison n = 168). Men were on average 64 years old, primarily White, and well educated. The difference in total decisional conflict was not significant (DCS total score; F[1,311] = .99, p = .32). The difference in cancer-related distress at 2 months between the intervention and the comparison groups was not significant (F[1,337] = .01, p = .93). Evaluation of specific decision processes indicated a significant effect on levels of perceived decisional support (intervention, M = 34.8, SD = 15.7; comparison, M = 38.3, SD = 16.1; F[1,337] = 3.74, p = .05). The intervention effect was greatest for nonwhite minority participants (b = -9.65, SE = 4.67) and those with lower educational attainment (b = 3.87, SE = 2.21). This interactive, comprehensive education and decision aid program may be most effective for a subset of prostate cancer patients in need of educational and decisional support.