This study was carried out during six successive seasons of 2020 till 2022 to development and evaluation six inbred lines of pumpkin (Cucurbita moschata) and their hybrids. Selection with self-pollination for six different cultivars was carried out for four generations. An evaluation experiment was conducted for twenty one genotyps (six parental inbred lines, twelve of their F₁ hybrids, and three reciprocals hybrids). Mean performance, heterosis percentages and potence ratio were estimated for vegetative, flowering, yield components and fruit quality characters. The results showed wide range of variability among the different genotypes for all studied traits. The estimated heterosis effects relative to both mid - and better - parents indicated that there were positive and negative values with different degrees for all studid charactrs. The estimated values of potence ratio illustrated that the inheritance of the four characters main stem length, number of days to first female flower, number of nodes to first female flower and total yield/plant, involved partial-dominance to over-dominance for taller over short plant, high over low number of days to first female flower, low over high number of nodes to first female flower and higher over low productivity, respectively. On the other hand, the inheritance of the other eight charactrs involved non-additive gene effects from partial and over dominance to partial and under-recessiveness. The three inbred lines P₁, P₃ and P₅ reflected the best desirable values for most studied characters; therefore, could be selected to produce the best hybrids. Concerning the F₁ hybrids; the three hybrids P₃×P₁, P₆×P₁ and P₆×P₄ showed the best performance for the various studied traits, varying according to the hybrid. Therefore, these hybrids are considered the best and most important in this study and could be considered as promising hybrids with distinguished specifications.