A field experiment was conducted at Nubaria agricultural research station during the 2007 and 2008 summer seasons. Two irrigation regimes e.g. 100 and 75% of maize water requirements, respectively, under drip irrigation system and ten (5 single-cross (SC) plus 5 three-way cross (TWC) maize hybrids and their interaction were assessed. The experimental design was a split-plot with three replications, where the main plots represented two irrigation regimes and the sub-plots were assigned to the ten maize hybrids. The main findings could be summarized as follows: Significant decreases in grain yield were observed under deficit irrigation comparing with adequate one in 1^st and 2^nd seasons. Plant height and ear height exhibited similar trends, however, the differences did not reach the significant level due to irrigation regimes. An opposite trend was recorded for number of days to mid-silking, anthesis -silking interval and leaf proline content traits, where 75% irrigation regime resulted in higher values of such traits in the two seasons of study, comparable with 100% irrigation regime.As for maize hybrid types, notable opposite trends in grain yield were found, where TWC hybrids average increased by 1.80% more than SC hybrids in 2007 season, meanwhile SC hybrids averaged surpassed that of TWC hybrids average by 1.87% in 2008 season. Additionally,TWC hybrids exhibited shorter values of days to mid-silking and anthesis- silking interval (day) compared with SC hybrids, in the two seasons of study. The average of leaf proline content was higher for SC hybrids, comparable with TWC hybrids. On average basis, SC hybrids exhibited higher value of (DSI) than TWC hybrids in 1^st and 2^nd seasons, and SC10 maize hybrid exhibited the potentiality of grain yield with the adequate irrigation regime, in 1^st and 2^nd seasons. Under 75% irrigation regime, TWC.321, TWC.324, TWC.327 and SC.162 exhibited higher grain yield in 2007, while in 2008, TWC.321, SC.10 and SC.162 gave higher grain yield.The amounts of applied irrigation water were 8000 and 6070 m³ ha^-1 for the 100% and 75% irrigation treatments, respectively. Average crop water productivity values increased with decreasing applied water, where, under 75% irrigation regime CWP was increased in 1^st and 2^nd seasons, comparable with 100% irrigation regime. Under stress conditions, average CWP value for the TWC hybrids was higher by 13.48% in 2007, and seemed to be negligible (0.79%) in 2008 season comparing with SC hybrids, respectively. An opposite trend was notable under 100% irrigation regime, where average CWP value for the SC hybrids was higher by 5.26 and 3.62%, respectively, in 1^st and 2^nd seasons. The highest CWP values (3.39 and 2.88 kg m^-3), respectively, in 2007 and 2008 seasons were obtained with SC10 hybrid as irrigated at 100% regime interaction.