This work was carried out to evaluate four summer squash cultivars, namely El-Eskandarani, Balady, Gabla, and Halap, at the Experimental Farm of the Faculty of Agriculture Ain Shams University at Barrage in the fall and early summer plantings during 2002/ 2003 and 2003/ 2004 seasons. Results showed great variations in plant vigor, fruit characters and productivity among the four summer squash cultivars. The vegetative growth and number of staminate flowers were larger in fall planting than those of summer planting in all cultivars, while the number of pistillate flowers and yield were higher in summer planting than those of the fall planting .Balady cultivar recorded the highest vegetative growth, while Gabla and Halap cultivars recorded the earliest and the highest yields.