This study employs stochastic DEA approach for measuring irrigation water efficiency of wheat farms in irrigated areas of Chbika (Central Tunisia). Data was collected from 170 wheat farms during 2010-2011cropping season. The empirical results show that the average water use efficiency calculated by this approach was only around 41% under CRS while it was 44% under VRS. This suggests that there is substantial scope for improving irrigation water use efficiency in the study region using the existing technology on wheat farms. A Tobit regression was used to identify the determinants of the irrigation water use efficiency in the studied sample. Results of the Tobit analysis show the positive effect on water use efficiency of variety choices, irrigation sources, membership in water users associations, irrigation management and experience. These results are valuable for policy makers since they can be easily integrated in the general guidelines of water valorisation policies.