The present study was carried out at the Agriculture Research Center, Islamic Azad University, Ardabil Branch, Ardabil, Iran, in 2010-2011 cropping year using Seimareh durum wheat cultivar, arranged as split-plot based on randomized complete block design (RCBD) under two drought stress conditions (normal irrigation and water deficiency) and four manganese sulphate fertilizer levels (control, 50, 100 and 150 kg/ha(-1)) with three replications. Analysis of variance showed significant interaction effect for traits at 0.01% level. The best level of fertilizer was 100 kg/ha, that increased yield in comparison to control. Also, results showed that agronomic efficiency of fertilizer under stress condition was higher than under normal condition. At fertilizer level of 100 kg/ha the agronomic efficiency of fertilizer was also higher. According to drought tolerance index, at 100 kg/ha fertilizer level was best in increasing stress tolerance. Results showed that 150 kg/ha level decreased tolerance to stress in Seimareh genotype. Positive effect of manganese sulphate fertilizer amount of 00 kg/ha on stress tolerance and performance can be encountered in the last dry season and also compensation for the negative effect of time delay in the cultures used.