From 1970 through 1983, 107 patients with newly diagnosed adenocarcinoma of the prostate were treated with radiotherapy with curative intent at Duke University Medical Center. Forty-five patients (42%) underwent transurethral resection of the prostate (TURP) for diagnostic and/or therapeutic purposes prior to beginning radiotherapy. Sixty-one patients (57%) were diagnosed by needle biopsy. TURP and needle biopsy groups were comparable (age, elevated acid phosphatase, early [A2, B] and late [C, D1] disease stages, and follow-up). TURP patients were more likely to have poorly differentiated tumors and were more often given concurrent hormonal therapy. Both univariate and multivariate analyses to study the effect of TURP on patients with prostate cancer treated with radiotherapy were done. We were unable to demonstrate any adverse impact of TURP on the outcome of radiation therapy for prostate cancer. This issue remains controversial and should be addressed in a prospective, randomized trial.