Development of single cross maize hybrids significantly boosted up the grain yield potential. Estimation of combining ability is key step in the development and evaluation of hybrids. A total six maize accessions viz. A556, OH-41, WFTMS, Q67, 82Pi and L7-2 were hybridized following Griffing’s Method 1, Model 1 in a complete diallel fashion (parental, direct and reciprocal combinations). Seeds from parental lines and all single and reciprocal crosses (30 F1s) were sown during autumn 2013 using randomized complete block design with three replications. Mean squares due to general combining ability (GCA), specific combining ability (SCA) and reciprocal effects for all characters were significantly different. The SCA Variance components were higher for ear diameter, ear length, grain rows per ear and grains per ear than GCA effects. However, GCA variance for seedling emergence and 100-grain weight were greater than variance due to SCA effects. Results revealed that inheritance of ear diameter, grain rows per ear and grains per ear was governed by non-additive type of gene action. WFTMS for seedling emergence, ear length and grain rows per ear, L7-2 for ear diameter, Q67 for grains per row, OH-41 for grains per row and 100-grain weight had higher GCA effects. Crosses A556 × 82Pi for seedling emergence, Q67 × L7-2 for ear diameter, WFTMS × Q67 for ear length, OH-41 × WFTMS for grain rows per ear, OH-41 × L7-2 for grains per row, 82Pi × L7-2 for grains per ear, A556 × WFTMS for 100-grain weight had higher SCA values.