The development of local squash hybrids or varieties that have the capacity for higher yielding and earliness over foreign cultivars or hybrids is a pressing need. The objectives of this study were to select the combinations which produce the best F1 by combining different germplasm in crosses. Furthermore, to study heterosis and the nature of gene action associated with this phenomenon. Four varieties belong to Cucurbita pepo L.; Militte (P1), Caserta Italian (P2), Zucchini Grey (P3), Eskandrani (P5) and one variety belongs to C. maxima Duch Abobrinha redonda (P4) were used in this study. In the summer season of 2014, these five varieties were selfed and also crossed to produce 20 F1 hybrids according to the complete diallel crosses mating design. In the spring season, 2015, all the F1 hybrids including their reciprocals and parental varieties were evaluated and grown in a randomized complete blocks design with three replicates. Data were recorded on the following traits: steam length (S.L in cm), the percentage of female flower (FF%), number of days to the first female flower (NDFF), early yield kg/plot (EY/P), number of fruits/plant (NF/P), average fruit weight (FW), total yield/plot (TY/P) and fruit length (FL). The performance of the five parents, the 10 F1 hybrids and their 10 F1r reciprocal hybrids were variable. The P5 appeared to be the best parent for vegetative traits. For yield and fruit traits, once more P5 was not only the best parent but also better than most the F1 hybrids for almost all traits. Heterosis from the better parent was not present for all vegetative traits where, many values were negative. The analysis of complete diallel crosses showed that both GCA, SCA and reciprocal were highly significant indicating their importance. The magnitude of GCA was always larger than SCA. The variances were larger than , although, variances were also present. These results were supported by absence of heterosis from the better parent. The hybrids including P4 as a male or a female parent would be consider as interspecific hybrids. The results indicated that the means of interspecific hybrids i.e. 1x4, 2x4, 3x4 and 4x5 and their reciprocals showed better performance from the other hybrids for many studied traits.