The field experiment was conducted in agricultural research field under the department of field crops, faculty of agriculture, University of Dicle, Turkey (37 degrees 53' N, 40 degrees 16' E) during spring wheat growing season of 2011-12 for assessing the grain yield and quality of sixteen spring wheat genotypes grown under late sown rainfed condition (high temperature combined with drought stress) as compared with early sowing in irrigated condition (favourable environment). The experiment was laid out in a split split plot design with three replications. Two sowing times: early sowing (cool environment) and late sowing (warm environment) were allocated in main plots, sub-plots were in two irrigation conditions (rainfed and irrigation) and finally sub-sub plots were arranged with sixteen spring wheat genotypes. Data on grain weight (GW), grain protein content (GPC), grain starch content (GSC), test weight (TW), Zeleny sedimentation volume (ZT), dry gluten content (DGC), gluten index (GI) and grain flour content (GFC) were determined to know the adverse effect of high temperature in combined with drought stress. The results of the present study indicates that high temperature combined with drought (late sown heat stress condition) significantly influenced the grain yield and quality parameters of all tested wheat genotypes. Grain protein content showed a positive correlations with DGC and ZT, while negative correlation with GW under normal and heat stress conditions. Moreover, a significant negative association was found between GSC and GPC content due to the adverse effect of high temperature in combined with drought stress. These results support that the performance of genotypes 'Inqilab-91', 'Cham-6', 'Adana-99' and 'Meta-2002' were better in respect of the most important traits of grain quality under adverse environment. Therefore, the genotypes may be considered as prospective good candidates for new wheat varieties for cultivation under heat (late sowing) and drought stress (rainfed) conditions of Turkey.