The aim of the present study was to evaluate growth performance parameters, antioxidant capacity, immune response, and hepatic and renal functions of APRI growing rabbits fed diets supplemented with zinc-oxide (ZnO) or nano-zinc oxide (ZnO-NP). A number of 60 weaned rabbits (5 wk of age) were divided into three experimental groups were fed a basal diet supplemented with 0 (G1), 50 mg ZnO (G2), and 30 mg ZnO-NP (G3) per kg during the growing period (5 to 13 wk of age). Live body weight, feed consumption, weight gain, feed conversion ratio, performance index and mortality rate were recorded. Biochemical parameters, antioxidant and immunity status were determined at 13 wk of age. Results show that dietary ZnO or ZnO-NP addition increased (P<0.05) growth performance parameters, serum high-density lipoproteins, glutathione, glutathione S-transferase and superoxide dismutase, immunoglobulins. Concentrations of triglycerides and MDA in blood serum reduced (P<0.05) in treatment groups. In conclusion, dietary supplementation with ZnO or ZnO-NP can enhance growth performance, lipid profile, immunity and antioxidant status of growing rabbits under heat stress conditions.