Heterosis and heterobeltiosis study was undertaken in maize during 2016 at Research area of Department of Plant Breeding and Genetics, Faculty of Agriculture, Gomal University Dera Ismail Khan, Pakistan. 8 x 8 diallel cross combination were made during spring 2016. All the F1’s hybrids along with their parents and two commercial check hybrids were evaluated in summer 2016. Data were recorded on plant height, ear height, ear length, no of kernels row-1, number of kernels rows ear-1 and 100-kernel weight. The analysis of variances (Table 1) revealed that mean squares due to progenies and their parents were highly significant for all the traits. All the cross combinations showed positive heterosis for plant height, ranged from +3.41% (SY204 x S-202) to +51.21% (A201 x IQ207). Twenty two crosses showed positive heterosis for ear height, the cross (J205 x Sy200) revealed maximum value of +23.90% for ear height, the cross (SY200 x J205) showed maximum value for standard heterosis +38.15 (33M15) and for (32B33) +43.19. For ear length all the crosses showed significant heterosis, mid parent heterosis ranged from -3.72% to 47.33% for the cross (S-202 x A201) and (P203 x S-206), most of cross combinations revealed negative values for standard heterosis over both commercial check hybrids. In case of number of kernels row-1, the crosses proved their superiority over parents, the heterosis ranged from -16.27% (S-202 x J205) to +44.73% (IQ207 x S-202), while heterobeltiosis values ranged from -18.18% (A201 x S-202) to +59.01% (SY200 x IQ207), standard heterosis ranged from -16.11% to +17.52% (33M15) and -27.72% to 8.93% (32M33) for all the crosses. Number of kernels rows ear-1 showed maximum heterotic contribution to high yield ranged from -5.26% (A201 x J205) to +26.31% (S-202 x S-206), while the magnitude of standard heterosis ranged from -18.18% to 13.63% (33M15) and for (32B33) was -21.73% to 8.69% for number of kernels rows ear-1. Significant heterosis was observed +57.11% in cross (P203 x S-206) for 100-kernel weight. Standard heterosis of all cross combinations over both commercial check hybrid ranged from -28.37% to +6.45% were recorded for (33M15) and (32B33) -23.70% to +12.30%.