Forecasting yield of crops is important for planners in taking tactical decisions for ensuring food availability. Crop simulation models are useful tool to forecast the crop yield. The CERES-wheat model calibrated and validated with experimental data was used to predict the district wise yield in Bihar. Based on the areas under different dates of sowing and crop cultivars, a correction factor was applied on simulated yield to predict the district wise and regional wheat yield. The simulated yield were higher than the actual yield in all the three agro-climatic zones, while the forecasted yields were very close to actual. The percentage deviation of the forecasted yield from the actual was ±4.0 %. The results clearly indicated that the CERES-W heat model can be used to regional production estimates of wheat in Bihar.