This study assessed the efficacy of a patient-controlled regional analgesia technique for either psoas compartment block or femoral nerve block after total knee replacement in 68 patients who were randomly divided into these two groups. All patients received 40 ml of 0.25% bupivacaine via femoral or psoas catheters before general anesthesia, and then, as patient-controlled regional analgesia, 10-ml boluses of 0.125% bupivacaine, with a lockout time of 60 min over 48 h. Pain scores, sensory block, supplemental analgesia, bupivacaine consumption, and side effects were recorded. All measured parameters were comparable in the two groups. Both techniques achieved a good quality of analgesia and satisfaction without any major side effect.