We compared the surgical pathological findings and postoperative course of patients with palpable and nonpalpable prostate cancers. All patients with untreated prostate specific antigen (PSA) 4 to 10 ng./ml. who underwent radical prostatectomy between December 1984 and December 1993 were reviewed to select 61 with clinical stage T1c (nonpalpable) with stages T2a to c (palpable) disease. Nonpalpable cancers were smaller (2.99 versus 4.42 cc for palpable tumors), had smaller volumes of Gleason grade 4 to 5 cancer (0.66 versus 1.32 cc, respectively) and were less likely to have positive surgical margins (13 versus 22%, respectively) or significant (1 cm. or more) capsular penetration (10 versus 26%, respectively). Nonpalpable and palpable cancers had similar rates of seminal vesicle invasion (3.3 versus 4.3%, respectively) and positive lymph nodes (1.6 versus 0%, respectively). More than 90% of patients with nonpalpable cancer were biochemically cancer-free postoperatively, and the remainder were alive with disease after a mean followup of 25.1 months, compared to 69% disease-fee, 28% alive with disease and 2.5% dead of prostate cancer after mean followup of 43.8 months among those with palpable disease. We conclude that nonpalpable prostate cancers are pathologically more favorable than palpable prostate cancers with PSA 4 to 10 ng./ml. Our preliminary results also indicate that nonpalpable cancers are less likely to recur postoperatively than palpable cancers with a similar PSA range.