From 1972 to 1986, 354 patients with local and locoregional adenocarcinoma of the prostate were treated with curative intent at the Medical College of Wisconsin. Fifty-six of these patients were found to have Stage D1 disease (evidence of pelvic lymph node involvement). Using external beam irradiation alone, these patients were treated aggressively to the pelvis followed by a boost to the prostate. The median dose to the prostate was 6800 cGy, and to the pelvis, it was 5040 cGy. The median period of observation after treatment was 9 years. Actuarial survival was 76% at 5 years, and disease-free survival was 61% at 5 years. Twenty-three patients had biopsy-proved pelvic lymph node involvement; the other 33 were considered to have Stage D1 disease based on abnormal computed tomographic scans, lymphangiograms, or both. Actuarial survival and disease-free survival were calculated for both groups separately, and there was no statistical difference in the results. Major complications occurred in 3.6% (two patients) of this group with Stage D1 disease. These results support the continued use of aggressive external beam irradiation in patients with locoregional adenocarcinoma of the prostate.