Combining ability for grain yield per plant and its components, quality traits and rust resistance was studied using five lines and seven testers and 35 crosses produced in line x tester mating system in durum and emmer wheat. Analysis of variance for combining ability revealed that variances due to females, males and female x male were significant for days to fifty per cent flowering, days to maturity, plant height, peduncle length, spike length, number of spikes/m2, number of tillers/plant, number of seeds/spike, total biomass/plant, thousand grain weight, grain yield/plant, harvest index, leaf rust reaction, protein content and semolina recovery. The general and specific combining ability variance ratio revealed the preponderance of additive gene action for all the traits except number of seeds/spike. Significant gca effects for grain yield and its component traits were exhibited by the lines Vijay and DK-1001 and testers DWR-1006 and Raj-1555. Fourteen crosses recorded significant sca effects for grain yield and related traits. The cross NIDW-15 X RAJ-1555 exhibited significant sca effects in the desired direction for leaf rust and protein content.