Fifteen newly developed yellow maize inbred lines were topcrossed to each of three inbred line testers, i.e. Gz. 658, Sd. 3118 and Sd. 3120 at Sids Agricultural Research Station during 2014 growing season. In 2015 season, resulting 45 topcrosses along with three commercial hybrids as check varieties, i.e. SC.162, SC.168 and SC.176, were evaluated in a replicated yield trail conducted at Gemmeiza and Sids. Data were recorded for days to 50% silking, plant and ear height (cm.), ear length (cm), ear diameter (cm) and grain yield adjusted to 15.5 % grain moisture. Combined analysis over the tow locations showed significant differences between the two locations for all studied traits except for grain yield. Mean squares due to crosses, lines and testers were significant for all studied traits. Mean squares due to lines x testers were significant for plant and ear height, ear diameter and grain yield. Mean squares due to lines x locations were significant for all studied traits except for ear diameter. Mean squares due to testers x locations were significant for all studied traits except for ear length. Mean squares due to lines x testers x locations interaction were highly significant for all studied traits except for ear length and ear diameter. The magnitude of δ2 GCA (average) was larger than that of δ2 SCA for days to 50% silking, plant height and grain yield. It was recommended that inbred lines 1 , 2 and 4 which possessed the highest GCA effects for grain yield may be considered promising lines for improving grain yield. Also, the crosses ( L7 x Gz. 658), (L8 x Gz. 658) and (L10 x Sd 3118) may be released for commercial cultivation after further testing and evaluation.