CERES-Rice model incorporated in DSSAT ver 3.5 was used to simulate the rice (var: IR 36) yields for the period 1973-2002. The input data required for running the model viz., soil and weather data were collected from the Departments of Soil Science and Agrometeorology of Indira Gandhi Krishi Vishwavidyalaya (IGKV), Raipur, respectively. The results revealed that the potential yields of rice varied from 81.97 to 105.50 q ha-1 and 39.74 to 89.49 q ha-1 under irrigated and rainfed conditions respectively during the study period. If years of different rainfall situations were considered the yield reduction due to water stress under rainfed conditions ranged from 3.87 to 61.44 q ha-1 as compared to irrigated conditions indicating that under good rainfall conditions the rainfed rice yields are as good as irrigated rice yields.