This study was conducted to investigate the influence of the dietary supplementation with different levels of ascorbic acid on growth performance, nutrients digestibility, and carcass traits of growing rabbits under summer and winter conditions in Egypt. Factorial design experiment (2×4) was carried out including two seasons (winter and summer) and four levels of ascorbic acid 0.0, 0.5, 1.0 and 1.5 g /kg diet. Results indicated that growth performance, daily feed intake, nutrients digestibility, nutritive values, hemoglobin, hematocrit, alanine aminotransferase (ALT), Red blood cell counts, dressing (%) and organs (liver, kidney and heart) weight were significantly decreased at summer season compared with winter season. In contrast, ascorbic acid supplementation caused a significant increase in growth performance indices, organic matter (OM) digestibility, some blood parameters i.e., aspirate amino transferase (ALT, AST, urea, total protein and albumin) of growing rabbits. However, ascorbic acid supplementation showed insignificant effects in dressing percentage and relative weights of liver, kidney, heart, lung and spleen. On the other hand, the economical evaluation in this study showed that using of 0.5 or 1g ascorbic acid/kg diet in winter season and 0.5 g ascorbic acid/kg in summer season in the growing rabbit diets was more economical than the other treatment groups. Conclusively, the results revealed that fortification of rabbit diets with ascorbic acid especially level of 0.5 g/kg diet, economically, could enhance the growth performance of growing rabbit during mild and hot climate in Egypt.