Prostate cancer is one of the most frequently diagnosed cancers in men. The rapid diffusion of the PSA Test and increased media attention has led to an increase in testing and incidence. Many men are now being identified as having latent or asymptomatic cancer. Prostate cancer is extremely complex with treatment variations depending on age, stage of disease and personal preferences. However, few comprehensive tools are available to guide men, their spouses and physicians through a shared decision process concerning treatment. This Phase I SBIR project will result in a prototype CD-ROM decision support system to be used in an outpatient setting, support group or at home to assist men diagnosed with prostate cancer in participating in the treatment decision. In Phase I we will 1) identify the necessary information and configuration of information to be given to a man diagnosed with prostate cancer to assist him in working with the physician to make decisions regarding treatment; 2) produce a prototype CD-ROM of the patient-oriented decision support system and 3) test the prototype with men recently diagnosed as having prostate cancer and spouses.