A group of 914 patients with carcinoma of the prostate treated by definitive radiotherapy at Stanford between 1956 and 1985 was studied. Of these, the initial hemoglobin level was recorded in 656 cases and the initial blood pressure in 760 cases. End-points studied in actuarial analyses were survival, disease-specific survival, local control, freedom from distant relapse, and occurrence of late intestinal complications. Although the anemic group (Hb less than 13.5 g/dl) was correlated negatively with survival (p = 0.02), there was no correlation with disease-specific survival or local control. The conclusion was that anemia per se did not affect the outcome of radiation therapy. A pulse pressure greater than or equal to 60 mm Hg was significantly correlated with worse survival (p = 0.01) and local control (p = 0.04), but no correlation was found between systolic and diastolic blood pressure and the end-points measured. Neither anemia nor hypertension were significantly correlated with late intestinal complications.