A sample of 46 social work departments (psychiatric social workers excluded) from various hospitals which went under the 1997 hospital accreditation was studied. 140 social work administrators and staff, plus 257 patients and families responded by providing annual reports, information on level of professionalism and quality of service (patients' satisfaction). This study was the first local one attempting to adopt production efficiency from economic approach to evaluate the performance of medical social work. Through examining data on departmental cost, professional manpower and service output, the purpose was to make relative comparison in production efficiency among the 46 departments. The results also suggested efficient reference set for those relative inefficient studied subjects. Based on the findings, implications and recommendations were made on management, implementation as well as policy-making levels.