Improving production efficiency is the main objective of government action to avoid efficiency losses and to increase the income of farmers. The aim of this study was to analyze performance levels of farms in the irrigated perimeter of Tadla in Morocco, according to the source of irrigation water. Thus, technical, allocative and economic efficiency were analyzed for farms in this area. To estimate the efficiency indices, the approach adopted is based on Data Envelopment Analysis method. Sixty samples of farms were chosen according to the mode of access to irrigation water. The results showed significant variability in technical, allocative and economic efficiency be- tween the observed farms. The source of irrigation water is an important determinant of farm performance in the Tadla region. Thus, the average of economic efficiency varies between 45% and 83% according to the source of irrigation water. In terms of water valuation, farms that use only groundwater achieve a better value of irrigation water (2.19 MAD 1 /m 3 ) in comparison with those that combine between surface and groundwater and those which are limited to the use of surface water.