Abstract: Fifty inbred lines of maize acquired from various sources, were screened in the warehouse for seedling traits under both normal and water deficit conditions and six diverse inbred lines were selected. The selected inbred lines were sown in the field for making all possible crosses in diallel mating fashion. The F1 crosses and their reciprocals along with the parents were sown in the field under both regimes using a replicated Randomized Complete Block Design. Data for various agro-physiological traits were recorded at different growth stages of the crop and then subjected to statistical analysis. Significant genetic variability existed for most of the traits under normal and moisture deficit conditions. The results for scaling tests showed fully adequate for the traits like 100-kernel weight, grain yield per plant, cell membrane thermostability, stomatal conductance and canopy temperature under normal condition while plant height, 100-kernel weight, grain yield per plant, leaf temperature and canopy temperature depression under water stress condition. The data were partially adequate for the traits like anthesis-silking interval, cell membrane thermostability and stomatal conductance under moisture deficit condition. All traits exhibited additive gene action under both regimes. Heritability estimates for yield related traits revealed maximum ability to transfer the desirable genes to the next generation.