Brown Hisex chicks were fed diets containing 2% and 5% Azadirachta indica leaf from their 7th to 35th day of age. Thereafter, the chicks were fed control diet for 2 weeks. A depression in body weight gain and efficiency of feed utilization was observed in chicks fed A. indica leaf when compared with the control. The main clinicopathological changes were increases in lactic dehydrogenase, glutamic oxaloacetic transaminase and alkaline phosphatase activities and uric acid and bilirubin concentrations and decreases in the total protein levels in serum. Changes in the values of erythrocyte count, haemoglobin concentration, packed cell volume, mean corpuscular volume and mean corpuscular haemoglobin were remarkable and associated with yellow discoloration on the legs and combs and hepatonephropathy. Tissue recovery was incomplete 2 weeks after removal from the experimental diets.