The present study aimed to determine the effect of L-arginine (L-Arg) supplementation in drinking water on the productive performance, biochemical traits, antioxidant status, carcass traits and economic efficiency of growing rabbit during summer conditions from July to September, 2020. Sixty male Baladi Red growing rabbits (35 days), were individually weighed and randomly divided into four equal treatment groups with five replicates (3 rabbits each). Rabbits were fed same pelleted ration ad-libitum. Each experimental group was supplied with drinking water from a separate container. The first group served as control (unsupplied), while the second, third and fourth groups supplemented with L-Arg in drinking water by levels 1, 2 and 3 g / L, respectively, during the experimental period (35 – 90 days of age). The results indicated that the group supplemented with 2 g L-Arg/L in drinking water had significantly improved body weight, body weight gain, performance index, relative growth rate percentage and feed conversion ratio at the end of the experimental period (90 day of age). The relative weights of pre-slaughter weight and total edible parts were significantly increased for the groups supplied with 1 and 2 g of L-Arg/L compared with other experimental groups. Triglyceride and high density lipoprotein concentrations for the group supplied with 2g L-Arg/L in drinking water recorded the significantly lowest values compared with the other groups and statistically equals with control group. Results of IgG, IgM, TAC and MDA for the group supplied with 2 g L-Arg/L were significantly improved compared with other experimental groups. In conclusion, supplementation growing rabbit males by 2 g L-Arg/ L in drinking water could improve productive performance, immunity and economic efficiency under summer conditions.