In this study, the light flashes program was used for raising growing rabbits during summer season under hot climatic conditions of Upper Egypt. Seventy two growing New Zealand white rabbits, six weeks old, were randomly divided into three experimental groups (24 rabbit/group): Group 1, the rabbits were subjected to 12 h constant light/day and was considered as a control (C); Group 2 (T1), the rabbits were subjected to 12 h light (6 h constant light and 6 h light flashes); Group 3 (T2), the rabbits were subjected to 12 h light flashes/day. Rabbits were reared under the same managerial, feeding and hygienic conditions throughout the experimental period. Besides, body weight (BW), body weight gains (BWG), feed intake (FI), feed conversion (FC), carcass traits, blood parameters and economical efficiency were estimated in this study. The achieved results confirmed that the productive traits (BW, BWG, FI and FCR) and economical efficiency of New Zealand white rabbits during the summer were better in the light flashes than in the constant light. It is worth to mention that AST, ALT, N / L Ratio, rectal temperature and mortality rate were significantly lower in light flashes than in constant light. Furthermore, lymphocyte, hematocrit, albumin and glucose increased relatively in light flashes groups. While, no significant differences were existed in blood protein, lipids, globulin, cholesterol and carcass traits percentages. Generally, it could be concluded that using light flashes in small and large farms owing to its beneficial effects on the productive traits of growing rabbits as well as lowering of electricity consumption which are considered of low cost, when compared with the costs constant light.