BACKGROUND: Obstacles to the use of patient-controlled analgesia (PCA) by elderly surgical patients have not been well documented. This study was designed to compare the effectiveness of PCA in an older and a young group, and the satisfaction of PCA use in older patients. METHODS: The 122 patients who received intravenous PCA during the first 48 hours postoperatively were divided into a young and older group. Visual analog scale (VAS) scores at rest and movement were assessed on 8, 16, 24, 36, 40, and 48 hours postoperatively. When the PCA was discontinued, satisfaction and concerns about it were assessed. RESULTS: There were no age differences with regard to pain at rest or with movement. Satisfaction with PCA was high and did not differ between the groups. CONCLUSIONS: Younger and older patients attained comparable levels of analgesia and were equally satisfied with their pain control. However we must have further studies to learn how effective PCA would be in a group over the age of 75 yrs.