Information on productivity of hospital personnel is required for optimum staffing and hospital management. This study deals with the quantitative aspects of workload of medical personnel in training hospitals by their specific characteristics. Specifically this study attempted to find relevant determinants of the productivity of medical personnel using multiple stepwise regression analysis based on data obtained from 135 training hospitals. The findings of this study were as follows: 1) Daily average number of outpatients and inpatients treated by a physician were 20.4 and 10.2, respectively. 2) Daily average number of patients cared by a nurse was 8.2. Daily average number of tests performed by pathologic technician and radiologic technician were 83.2 and 21.5, respectively. 3) Productivity of medical personnel were significantly different for the three groups of factors: hospital sire (number of beds, number of medical personnel per 100 beds): institutional characteristics (medical school affiliation, training type, profit status); and environmental factors (location, number of physician and beds per 1,000 population in the region). 4) The factors a(footing the productivity varied according to the types of medical profession: the number if beds, the number of physicians per 100 beds, training type, and profit status for physicians; the number of nurses per 100 beds, the number of beds, medical school affiliation for nurses; the number of physicians per 100 beds, the number of technicians per 100 beds, and ownership for pathologic technicians; the number o( technicians, training type, and the number of physicians per 100 beds for radiologic technician.