In a prospective clinical study we compared the hemodynamics and clinical symptoms following regional blocks and general anesthesia. 115 patients undergoing transurethral resection of the prostate were randomized to spinal (n = 62) and epidural (n = 53) blocks. An additional 10 patients received general anesthesia. Calf arterial flow, determined by strain gauge plethysmography (SGP), was similar pre- and postoperatively in the regional block groups but decreased in the general anesthesia group (p less than 0.05) on the 5th postoperative day compared to the preoperative day. On the 2nd and 5th postoperative days, venous capacity was lower (p less than 0.05) after general anesthesia compared to regional blocks. Antiembolism stockings offered no hemodynamic or clinical advantages. During the hospital stay (screening by Doppler and SGP) and 3 months of follow-up, no deep vein thrombosis or pulmonary embolism was diagnosed. 3 months after the operation, unspecific pain and/or weakness in the legs were reported by 12 patients in the spinal group, while the epidural group remained asymptomatic (p less than 0.01). We conclude that the predictive value of negative Doppler and SGP findings is good and that spinal and epidural blocks are hemodynamically advantageous as compared to general anesthesia.