A simple crossbreeding experiment between Gabali (G) bucks and Hyplus (H) does was performed to estimate crossbreeding effects for post-weaning growth traits (body weight at 5 (BW5), 7 (BW7), 9 (BW9), 11 (BW11), and 13 (BW13) weeks of age and daily weight gains (DG) during (DG5-7), (DG7-9), (DG9-11), (DG11-13) and (DG5-13), weeks of age). Estimates of heritability were mostly low or moderate for growth traits and ranged from 0.12 to 0.35 for body weights and 0.05 to 0.66 for daily weight gains. The percentages of direct additive genetic effects on body weights favored (p ≤ 0.01) the Gabali breed by 22.1, 31.2, 32.8, 31.1, and 25.2% at 5, 7, 9, 11, and 13 weeks and by 35.4, 38.1, 21.9, 3.7, and 27% for DG5-7, DG7-9, DG9-11, DG11-13, and DG5-13, respectively. The percentages of maternal effects ranged from 22 to 34.8% for body weights and ranged from 4.7 to 43.4% for daily weight gains. The percentages of direct heterosis were significantly positive by 11, 19.1, 20.3, 19.7, and 16.5% for body weights at 5, 7, 9, 11, and 13 weeks and by 25.6, 27.2, 17.3, 3.5, and 17.9% for DG5-7, DG7-9, DG9-11, DG11-13, and DG5-13, respectively. These results suggest that the Gabali breed could be used as a sire-group and the Hyplus line could be used as a dam-group to create new high growth rabbit lines in Egypt.