Abstract: This experiment was conducted to determine water use efficiency of chickpea (cv. Arman) under water deficit condition and different mineral N application. The experiment was arranged in growth chamber of Mohaghegh Ardabili University, Ardabil, Iran, in 2007, with three nitrogen levels (25, 50 and 75 kg N ha-1 as urea) and five irrigation regimes (soil water content of 25, 45, 65, 85 and 100% field capacity). The experiment was laid out in randomized complete block design (factorial) experiment with three replications. Results showed that water stress affect Water Use Efficiency (WUE), Relative Water Content (RWC), Leaf Area (LA), leaf number after stress induction, biomass (above ground tissues) and root/shoot ratio (R/S) traits. Application of Mineral nitrogen increased water use efficiency, RWC, leaf area and biomass. Maximum amount of WUE, RWC, biomass and LA obtained from 75 kg N ha-1 under water deficit condition. This experiment revealed that nitrogen fertilizer could reduce many detrimental effects of water stress. These results also suggest that using of nitrogen fertilizer in water deficit conditions (such as dry land farming areas) increase tolerance of plants to stress.