Twenty-four New Zealand white × Chinchilla weaner bucks, aged between 7 and 8 weeks and averaging 0.9 kg in weight, were divided into four groups of six each and used in a 12-week feeding trial to evaluate the blood biochemistry and haematology of rabbits fed sun-dried, ensiled, and fermented cassava peel-based diets. The test diets designated A, B, C and D were completely randomised. Diet A, the control, was a 16.18 per cent CP (crude protein) weaner ration formulated from maize, maize offals, soya bean meal, blood meal, oyster shell, bone meal, vitamin premix, and common salt. Diets B, C and D were also weaner rations of, respectively, 16.10, 16.20 and 16.08 per cent CP in which 10 per cent maize of the control diet was replaced, respectively, with sun-dried, ensiled and fermented cassava peels. The diets were roughly iso-caloric. The haematological components of the study included packed cell volume (PCV), white blood cells (WBC), neutrophil (N), and lymphocytes (L). The biochemical parameters were serum creatinine, urea, bilirubin (total and conjugated), serum glutamic transaminase (SGPT), serum glutamic oxaloacetic transaminase (SGOT), eosinophil, and blood sugar. Liver and kidney weights were also monitored. The results showed that PCV, WBC, N and L were affected (P<0.05) by experimental diets. Also affected (P<0.05) were bilirubin, SGPT and SGOT. However, serum creatinine, urea and eosinophil were unaffected (P>0.05) by treatment diets. Liver and kidney weights also did not differ (P>0.05) among rabbits fed different dietary treatments.Original scientific paper.