INtroductIoN Maize occupies the highest percentage of most compounded rations for monogastric animals, taking about 40-60% their diet (Onimisi and Dafwang, 2010).The increasing pressure on the use of maize by human population and livestock feed millers coupled with the cost of maize which fluctuates with the seasons of the year, thus making the cereal grain to be either scarce or expensive, stimulate the use of alternative sources of energy that are research Article Abstract | The increasing pressure on maize for human and livestock nutrition, coupled with the cost of maize which keeps increasing, stimulate the use of alternative and locally available sources of energy. This study aimed at contributing to chicken productivity by evaluating effect of pelleted diets with graded inclusion levels of cassava-sweet potato meal (CASPM) as energy substitute for maize on the digestibility, carcass and haematological parameters of Cameroon Kabir chickens. A completely randomised design was used to allocate a total of 315 Kabir chickens (270 hens and 45 rosters) of 23 weeks of age to five dietary formulations T1 (0% replacement of maize with CASPM considered as control diet), T2 (25%), T3 (50%), T4 (75%) and T5 (100%). Animals within the treatments were balanced for weight in each sex, each treatment having 63 Kabir chickens in three replicates of 18 hens and 3 roosters each. The apparent digestibility of metabolizable energy was found to be positive. Lipids apparent digestibility value was negative for diet but positive for other treatments. Crude protein, Ash and crude fibre were all negative irrespective of treatments. The rosters had higher carcass weight than the hens (P<0.05), which in turn had a higher liver to carcass ratio as well as abdominal fats compared to the rosters. No significant difference was observed among other organs. The lowest RBC count was registered for T5 whereas unusual high RBC count was observed for hens from T4. T5 (100% substitution) and T3 (50% substitution) had the highest digestibility mean while T3 (50% substitution) had the lowest FCR. T1 and T3 were found to have the best optimum range blood characteristics. Overall, T3 was the best of the five treatments as neither mortality nor adverse effects on chickens was recorded. Besides, no abnormalities were found upon carcass analysis. It is therefore recommended that 50% substitution of cassava-sweet potato meal as energy substitute for maize shall be used for the improvement and productivity of Kabir chicken production. Keywords