The aim of the study was to evaluate the physiological performance of heat stressed growing rabbits fed diets supplemented with vitamin anti-oxidants and bicarbonate buffers. A total of thirty (30) growing rabbits (New Zealand White crosses) of two months old were used in this study. There were six (6) rabbits per treatment in a Completely Randomized Design (CRD). The treatment groups consisted of: Control, Sodium Bicarbonate (NaHCO3) and Potassium bicarbonate, (KHNO3) solution respectively, Vitamin C, and baobab fruit pulp meal (BFPM) as supplements respectively. The experiment lasted for 9 weeks. Five (5) ml of blood were collected from five rabbits (through the ear vein) chosen randomly from each group of rabbits respectively at the beginning and the end of the experiment for serum metabolite and thyroxine hormone evaluation. Physiological performance of the rabbits was also evaluated. It was found that environmental conditions were stressful to the animals; Vitamins (Vit C and BFPM) significantly (P<0.05) reduced rectal temperature, heart rate and triglycerides compared to other treatments. The buffers recorded significantly (P<0.05) high feed intake, calcium and thyroxine. It was concluded that ameliorating heat stress with the antioxidants were helpful to improve the performance of rabbits and was recommended to be included in rabbit diets during the hot period.