Many clinically important predictive factors in prostate cancer are derived from light microscopic examination of tissue specimens by the pathologist. Two separate international consensus conferences held in 1999 addressed the contemporary status of such prognostic factors, sponsored by the College of American Pathologists (CAP) and the World Health Organization (WHO). Both conferences concluded that the following factors are recommended for routine use based on evidence from multiple published trials: TNM stage, histological grade using the Gleason system, surgical margin status, and serum prostate-specific antigen concentration. The WHO conference additionally recommended use of WHO nuclear grade, location of cancer within the prostate, and pathological effects of treatment. Other factors were categorized as promising or of unproven utility, including a wide variety of histopathologic and genetic markers. Standards are needed for analysis and quantitation of methods of tissue analysis, particularly for immunohistochemical studies and genotypic studies. This report describes the recommendations and conclusions of these two conferences.