The commonly employed methods for the early detection of urologic cancers remain the traditional techniques of a carefully performed history and physical examination. Newer developments include, among others, prostate-specific antigen and monoclonal antibodies in prostate cancer, flow cytometry in bladder cancer, computerized axial tomography (CAT) scanning in renal cancer, and ultrasound in testicular cancer. These and other new diagnostic techniques, with further testing and wider use, will hopefully permit the earlier diagnosis of genitourinary cancer.