Experiment was conducted to study the effect of irrigation regimes on growth and yield of 3 sesame cultivars during March 15, 2000 to June 9, 2000 at KMITL. A split plot design in RCB with 3 replications was used. Three sesame cultivars (Uborn Ratchatani 1, KKU3 and KU18) were main plots. Sub plots were 5 irrigation regimes based on the ratios of irrigation amount (IW) to cumulative evaporation (E) (i.e., 0.1, 0.3, 0.5, 0.7 and 1.0). The results revealed that Uborn Ratchatani 1 gave the highest total dry weight, seed yield and yield components followed by KKU3 and KU18, respectively. Total dry weight significantly increased with increasing the amount of irrigation from IW/E 0.1 to IW/E 1.0. With increasing of higher ratio of IW/E, the plants produced a larger seed yield and yield components. Uborn Rachatani 1 had a highest values of transpiration rate and total conductance but the value of leaf temperature was not found to be significantly different among the cultivars. The lower water regimes increased leaf temperature whereas transpiration rate and total conductance were reduced. However, water use efficiency (WUE) decreased form 12.57 kg/rai/mm in the treatment of IW/E 0.1 to 9.83 kg/rai/mm in the treatment of IW/E 1.0. Comparison amoung the 3 sesame cultivars, water used and WUE of Uborn Ratchatani 1 was the highest while KU 18 was the lowest.