The survival advantages associated with different treatments for localized prostate cancer (PCa) continue to be uncertain. We evaluated patients' use of an interactive CD-ROM-based decision aid designed to improve informed decision making about PCa treatment. Newly diagnosed, early-stage PCa patients who had not made a treatment decision completed a baseline telephone interview (N = 132), were mailed the CD-ROM, and completed a one-month follow-up interview (N = 120; 91%). Compared to non-users (21%), CD-users (79%) preferred to make an independent rather than a shared treatment decision (OR = 3.5, CI 1.2,10.5). The majority of users (63%-90%) responded positively regarding the length and clarity of the information. Further, 76% reported using the CD as much/more than other information sources. A preference for having less decisional control predicted greater satisfaction with the CD (F[7,87] = 4.75, p< .05). Electronic utilization data revealed that the topics most accessed concerned treatment information and that users spent over an hour using the CD (median = 72 minutes). This electronic educational tool was well-accepted by patients and may be particularly useful for patients who desire less control over their treatment decisions and who are less proactive in seeking information on their own.