The objectives of this study were to calculate heterosis of twelve inbred lines of white maize and identify good hybrids based on grain yield data and other yield-related traits. Thirteen inbred lines (13) were crossed in 2017 with two inbred line testers using a line by tester mating design. Twenty-six crosses were generated and evaluated in a randomized incomplete block design (RCBD) with two standard checks and 3 replications during the long rainy seasons between June to December, 2018 at Bako National Maize Research Center, Ethiopia. Also, adjacentto the hybrid trial, thirteen parental lines with the two tester lines were evaluated using RCBD with three replications. Mean separation was done using least significant differences (LSD). The overall mean grain yields (GY) of the genotypes (crosses) were 6.32 t/ha ranging from 5.21 t/ha to 8.19 t/ha. Heterosis for mid parent, better parentand standard were estimated for inbred lines. The highest significant positive heterosis over the best standard check for GY was recorded for L10 XT2 (334.21%). Inbred lines that showed positive heterosis over better parent and midpart for GY can used for germplasm source for maize breeder
