The purpose of this study were to analyze work patterns of clinical dietitians by time study, to investigate labor time used in each clinical dietetic activity, and to develop standardized indices of clinical dietetic staffing needs. Two general hospitals(A & B) in Seoul were selected for study. The results of this study can be summarized as follows. 1) For the A hospital, the percentage of clinical dietetic activities such as attending meeting, professional research, foodservicemanagement, clerical activity for the foodservice, administrative activity and delay were 17.5%, 1.3%, 14.5%, 23.4%, 21.3%, 4.6%, and 17.3% respectively, while 22.4% 3.5%, 23.7%, 10.9%, 15.8%, 4.2%, and 19.5% respectively for the B hospital. 2) For the A hospital, the percentage of direct patient care like outpatient nutrition education, group nutrition education, and patient meal planning were 69.5%, 10.5%, 7.6%, and 12.4% respectively while 78.9%, 7.3%, 8.9%, and 5.1% respectively for the B hospital. 3) Time spent for performing direct patient care such as basic care, intermediate care, and indepth care per patient were 28.0min, 73.1min, and 53.0 min respectively for the A hospital, while 45.3 min, 76.2 min, and 52.6 min respectively for the B hospital. 4) Full time clinical dietitian staffing needs were calculated for the three parts ; basic care, intermediate care, and in-depth care. For A hspital, the appropriate numbers of full time clinical dietitian were 3.5 persons in basic care, 3.6 persons in intermediate care, and 1.3 persons in in-depth care, while 6.1 persons, 6.3 persons, 3.2 persons respectively for B hospital.