This investigation was carried out to study the combining ability and heterosis in a half diallel mating among seven bread wheat varieties. Some traits i.e. days to heading, plant height, no. of spikes/plant, spike length, no. of grains/spike, 1000-grain weight and grain yield/plant were studied. The results showed that there were highly significant estimates of both GCA and SCA combining ability effects, indicating the relative importance of additive and non-additive genetic variances for all studied characters. The ratios of GCA/SCA were more than unity in all studied traits, indicating that additive gene effects were more important than dominance in the expression of these traits. Shandaweel-1 (P₂) had positive significant for plant height and negative significant for days to heading, while it gave non-significant values for spikes number plant^-1, grains number spike^-1, 1000-grain weight and grain yield/ plant^-1. Gemmeiza-11 (P₃) gave positive and highly significant GCA effects for days to heading, no. of grains/spike and grain yield/plant^-1 and negative highly significant for no. of grains/spike and GW, while it had non-significant for PH. The parent Giza-171 (P₄) was good combiner for PH and GW, while Sakha 93(P₇) was the best combiner for DH, PH, GW and grain yield plant^-1. P₃×P₇ showed the maximum positive SCA effects, while P₁×P₂ displayed the highest negative SCA effects. Concerning grain yield/plant^-1, the crosses P3×P₆ and P₃×P₇ gave the highest positive significant values for the heterosis over mid parent and better parent.