We describe the development and evaluation of a videotape decision-aid to assist patients in considering treatment options for clinically localized prostate cancer. The content and form of the videotape were developed utilizing literature review, an expert opinion panel and patient focus groups. Thirty-two men, aged 50-85 years, who did not have prostate cancer underwent pre- and post-videotape testing. A quantitative analysis found the videotape to be moderately effective in improving short-term recall of treatment options and outcomes. Qualitative analysis demonstrate that after viewing the videotape, subjects were more likely to consider an active role in the treatment decision-making process. We conclude that a videotape decision-aid will benefit clinical practice by conveying knowledge to patients regarding treatment options and outcomes and encouraging them to participate with their physicians in medical decision-making.