A half-diallel cross was performed among five inbreds of cucumber to obtain ten gynoecious F₁ hybrids suitable for the greenhouses culture. Theses genotypes were used to study the general combining ability (GCA) and specific combining ability (SCA) and to illustrate their relation to the type of gene action for some quantitative traits. All entries were evaluated in greenhouses in two consecutive seasons of 2004/05 and 2005/06. Traits evaluated included relative increasing in plant height, length of stem internodes, number of lateral branches, number of leaves on stem, days to anthesis, early yield , total yield , average fruit weight, fruit length and fruit diameter. The combining ability analyses showed that GCA and SCA mean squares were significant for all studied traits in both growing seasons. The magnitudes of GCA mean squares were larger than SCA mean squares and the GCA:SCA ratios had values over than unity at both seasons. It could be concluded the importance of both additive (GCA) and non-additive (SCA) genetic variances in the inheritance of studied traits. In addition, the additive effects (GCA) were relatively more important than non-addirtive effects (SCA) in the expression of such traits. It is suggested that selection could be effective in improving new recombininat inbreds and also developing superior hybrids is possible.