This is a retrospective analysis of 225 patients with localized adenocarcinoma of the prostate who were treated with continuous-course external-beam radiation therapy at the University of Florida between October 1964 and August 1982. All patients were treated 5 or more years prior to the date of analysis, and 30% were eligible for 10-year follow-up. Hormonal treatment was used only in the management of recurrent disease. Ten-year results by stage were as follows: local control--A, 96%; B1, 92%; B2, 51%; C1, 57%; C2, 76%. Relapse-free survival--A, 96%; B1, 58%; B2, 38%; C1, 43%; C2, 61%. Absolute survival--A, 69%; B1, 29%; B2, 47%; C1, 35%; C2, 50%. Freedom from distant metastasis--A, 100%; B1, 55%; B2, 71%; C1, 65%; C2, 77%. Tumor grade was an important prognostic variable in most of the subgroups analyzed. The 5-year rate of distant metastasis was significantly greater in patients with stage C disease when the biopsy was made by transurethral resection of the prostate (TURP) rather than by needle biopsy. In stage B patients, the biopsy method was not prognostically important. For the 48 patients who developed recurrent tumor in the prostate gland, with or without concurrent metastasis, the 5-year absolute survival rate calculated from the date of recurrence was 26%, compared with 10% for the 34 patients who developed distant metastasis alone. Severe complications developed in 5 out of 225 patients (2%) and included three severe rectal injuries, one bladder neck contracture, and one femoral head necrosis. Moderate complications developed in 48 out of 225 patients (21%), with rectosigmoiditis (8%) and hematuria (5%) being the most common problems. For both moderate and severe complications, there was a clear trend toward an increasing complication rate with increasing dose. The method of diagnosis appeared to be a factor in the development of urinary incontinence following irradiation: needle biopsy, 0/106 (0%); TURP, 3/112 (3%); subtotal prostatectomy, 1/7 (needle biopsy versus TURP or prostatectomy, p = 0.076). The frequency of peripheral edema following irradiation was influenced by a history of surgical disruption of the pelvic lymphatics: staging lymphadenectomy, 2/16 (13%), versus no lymphadenectomy, 0/209 (p = 0.005). A comparison with other series is presented.