Sesame ( Sesamum indicum L.) is one of the most important oilseed crops in the world. It is well suited to different crop rotations. Water resources are limited for irrigation worldwide. Drought stress is one of the most important environmental factors limiting sesame production. Irrigation is of great importance to sesame production in arid and semi-arid environments due to positive effects on yield. The effects of water deficiency can be reduced by inoculation of plant roots with mycorrhiza fungi. In this experiment, the objective was to determine the effects of different levels of water application (60, 80, 100 and 120% of soil moisture depletion) by surface drip irrigation (T-tape) method and inoculation of plants with mycorrhiza ( G. mosseae ), on yield, yield components and WUE ag (overall agronomic efficiency of water use) of sesame. The field experiment was conducted at the Agricultural Research Farm of Isfahan University of Technology, Isfahan province, in 2011. This area has an arid climate. The experiment was arranged using a factorial design based on randomized complete block design with three replications. The amount of water used was based on daily soil moisture reading during growing season. Results showed that the effect of amount of water application (irrigation regime) on plant height, stem diameter, number of capsules per plant, capsule length, number of seeds per capsule, shoot dry weight, seed yield, harvest index, oil and protein yield and concentration of P in shoots and roots was significant (P 0.01). The effect of mycorrhiza application on seed yield and oil yield (P 0.05) and WUEag and concentration of P in shoots and roots (P 0.01) was significant. The maximum seed yield (2858.05 kg/ha) and oil yield (1698.94 kg/ha) of sesame was achieved in irrigation regime of 120% water requirement and mycorrhiza inoculation and in irrigation regime of 100% water requirement and mycorrhiza inoculation, respectively. The minimum seed yield (1460.2 kg/ha) and oil yield (774 kg/ha) were achieved in irrigation regime of 60% and non-inoculated. The effect of irrigation regime on WUE ag of seed yield, was not significant, because results revealed significant linear relationship between amount of irrigation water and seed yield. But the effect of mycorrhiza fungi on WUE ag of seed yield was significant (P 0.01). The highest WUE ag of seed yield (0.74 kg/m 3 ) was belonged to irrigation regime of 80% water requirement and mycorrhiza inoculation and the lowest WUE ag of seed yield (0.53 kg/m 3 ) was belonged to irrigation regime of 60% and non-inoculated. The effect of irrigation regime and mycorrhiza fungi on WUE ag of oil yield, were significant. The highest WUE ag of oil yield (0.43 kg/m 3 ) was belonged to irrigation regime of 100% water requirement and mycorrhiza inoculation and the lowest WUE ag of oil yield (0.28 kg/m 3 ) was belonged to irrigation regime of 60% and non-inoculated. According to economic analysis, the highest economic profit was recorded for the treatment of 80% and mycorrhiza inoculation and 100% and mycorrhiza inoculation of seed yield and oil yield, respectively. The results showed that deficit irrigation reduced sesame yield, and inoculation of the plants with mycorrhiza improved the performance of sesame under water stress through its positive effects on nutrient uptake. In drought years, it is suggested that tape irrigation method be used, with mycorrhiza application, in 80% water requirement, to save water consumption. Keywords: Sesame, Mycorrhiza, Surface drip irrigation, Water stress