Patients often want considerable information about their conditions, and enhanced patient participation might reduce unwanted practice variation and improve medical decisions. The authors assessed how men with benign prostatic hyperplasia reacted to an education program designed to facilitate participation in decisionmaking, and how strongly ratings of their symptom state and the prospect of complications predicted their treatment choice. A prospective cohort study was conducted in three hospital-based urology practices: two in prepaid group practices, and one Veterans Administration clinic. Four hundred twenty-one men with symptomatic benign prostatic hyperplasia without prior prostatectomy or benign prostatic hyperplasia complications were enrolled, and 373 provided usable ratings. Subjects participated in an interactive videodisc-based shared decisionmaking program about benign prostatic hyperplasia and its treatment options, prostatectomy, and "watchful waiting." They rated the length, clarity, balance, and value of the program and were followed for 3 months to determine if they underwent surgery. Patients rated the program as generally clear, informative, and balanced. Across all three sites, 77% of patients were very positive and 16% were generally positive about the program's usefulness in making a treatment decision. Logistic models predicting choice of surgical treatment documented the independent importance of negative ratings of the current symptom state (odds ratio 7.0, 95% confidence interval 2.9-16.6), as well as the prospect of postoperative sexual dysfunction (odds ratio 0.20, 95% confidence interval 0.08-0.48) in decisionmaking. Patients rated the Shared Decisionmaking Program very positively and made decisions consistent with their assessed preferences. These results suggest that patients can be helped to participate in treatment decisions, and support a randomized trial of the Shared Decisionmaking Program.