This study was carried out to examine the effect of water stress on growth and yield of two mung bean cultivars DX22 and VN5 in the pot experiment under nethouse condition in comparison with full irrigation. For water stress treatments, irrigation was withheld at three developmental stages: beginning of flowering, full bloom and pod filing. Water stress was imposed until 70 percent of plants or 75 percent of leaves per plants withered and afterward the plants were rewatered for recovery, growth and yield assessment. Under water stress conditions, the rate of photosynthesis, rate of transpiration, pods per plant, and individual grain yields were all adversely affected. Grain yield reduction (weight of 100 seeds and seed yield) was greatest when water deficit occurred at the pod filling stage.