The present study investigated the effects of dietary curcumin or nano-curcumin on carcass traits, caecum activity, caecum microbial count and haematological parameters of growing rabbits reared under heat stress conditions. APRI line growing rabbits (n=100, 5-wk of age) were distributed to five equal groups (n=20/group). Rabbits in the 1^st group were fed a control diet without any additives, whereas 2^nd, 3^rd, 4^th and 5^th groups were fed control diet supplemented with curcumin (25 or 50 mg), and nano-curcumin (2.5 or 5 mg)/kg diet up to 13-wk of age. Carcass traits, meat chemical composition, pH values of gastro-intestinal tract contents, caecum activity, caecum microbial counts, and haematological parameters were determined at 13-wk of age. The mean temperature-humidity index during the experimental period was 29.54. Results showed curcumin or nano-curcumin levels increased (P<0.05) count of red blood cell and platelets, and caecum activity parameters (ammonia nitrogen and volatile fatty acids), while reduced (P<0.05) white blood cells, total microbial and E. coli counts in the caecal content. Haematocrit value increased (P<0.05) only by nano-curcumin groups (2.5 or 5 mg/kg diet). Carcass traits, chemical composition of meat and pH values of gastro-intestinal tract contents were not significant among groups. Dietary curcumin or nano-curcumin levels, as natural antioxidants and growth promoters, can alleviate adverse impacts due to heat stress on caecal activity and health status without affecting the carcass traits of growing rabbits. Generally, the dietary addition of curcumin in nano-particles form could contribute to produce healthy and high-quality rabbit's meat for human consumption.