The present study was carried out during successive growing seasons for the years 2014 and 2015, under greenhouse conditions, at Sabahia Horticulture Research Station, Alexandria Governorate, Egypt. Six inbred lines of cucumber were utilized in a half-diallel cross breeding program to obtain 15 F1 hybrids. The breeding program was concerned with powdery mildew resistance, economic characters and their attributes; i.e. total fruit yield/ plant, number of fruits/plant and average fruit weight; in addition to the fruit quality characteristics; i.e., fruit length and fruit diameter. Results showed that the hybrid P2×P4 gave a very high resistance (100%), which is considered an immune (I) hybrid, while, the genotypes P2, P1×P2, P1×P3, P2×P5 gave high powdery mildew resistance (HR); i.e., (98.33%, 98.23%, 96.3% and 95.83%), respectively. The additive gene action exhibited highly significant, positive or negative, values in all the tested crosses for total yield/plant; whereas, the dominance effect values were found to be positively high significant in most crosses. The additive gene action exhibited positive significant values for powdery mildew resistance in most crosses; except the cross P1×P2, which gave a negative high significant values and the two crosses P1×P5 and P2×P3, which gave insignificant values. The dominance gene action was found to have positive high significant values in most crosses for this character.