One of the major tasks of medical workforce planning system is establishing a balance between physician supply and demand throughout the country. There are different methods for estimating of SPECIALIST demand, one of them is estimation of future demand based on current demand. In this study, attendance to SPECIALISTs during two weeks and/or hospitalization during one year before initiating the study had been considered as a criterion for demand estimation. Ten thousands urban families (45518 people) in 400 clusters (each containing 25 families) were studied in 17 districts. According to the results, it is predicted that there will be a physician oversupply in pediatrics, OB/GYN, and general surgery specialties until the years 2003-2004.