The experiment was conducted with the aim of determining the response of weaner rabbit to dietary ascorbic acid (AA) supplementation in hot environmental area of Makurdi, Nigeria. Twenty weaned rabbits of both sexes, aged between 6-8 weeks with an initial weight of 620 ± 42.95g in a 56 day trial. The animals were randomly allocated to two treatment groups with 10 rabbits per treatment in a completely randomized design. The experimental group was administered AA at the dose of 200 mg/kg, dissolved in 4 ml of sterile water orally, while the control group was administered with sterile water (4 ml) without AA per os. Both the experimental and control groups were given feed and water ad libitum. Records of feed intake and body weight were determined weekly for 8 weeks. At the end of the trial the animals were slaughtered by the throat-cut method and dressed to determine the dressing percentage and the relative cut-up parts. During the slaughtering 4 ml of blood sample was collected directly from each animal into Bijou bottles containing anticoagulant. Haematological parameters of packed cell volume was determined using micro-haematocrit method, haemoglobin concentration using cyanmethaemoglobin method, total erythrocyte count and total leukocyte count using the haematocytometric method while erythrocyte osmotic fragility was determined by the method of Faulkner and King (1970). The results indicated that the daily weight gain recorded in the experimental group was 8.93 ± 0.72 and significantly (P < 0.05) greater than 7.05 ± 0.51 obtained in the control animals. Also the feed to gain ratio in the control rabbits (6.07 ± 0.47) was significantly (P < 0.05) greater than the obtained value in the experimental rabbits (5.27 ± 0.60). Carcass weight obtained in the experimental animals was significantly (P < 0.05) higher than the recorded value in the control animal. All other haematological parameters results except neutrophil, eosinophil, basophil and monocyte obtained in the experimental animal was significantly (P < 0.05) higher than that of the control animal. The percentage haemolysis observed in the control animals was significantly (P < 0.05) greater than the observed value obtained in the experimental animals making the fragiligram of the control animals to be shifted towards right.