Two hundred and thirty-four total hip replacements in 199 patients performed by one surgeon were reviewed to compare the effects of spinal and general anesthesia. The amount of total blood loss was reduced an average of 600 milliliters in patients under spinal anesthesia. The amounts of operative blood loss, postoperative suction drainage, and blood replacement were also reduced very significantly (p smaller than 0.001). The patients in the two anesthesia groups were similar as to sex, age, body weight, pre-existing medical disease, preoperative medications administered, hip disease, type of prosthesis used, position during surgery, and anticoagulation regimen. The postoperative complications were fewer in the spinal anesthesia group. It is concluded from this study that spinal anesthesia is to be preferred over general anesthesia in patients undergoing total hip replacement.