The study was conducted to assess the effect of replacing maize with cooked mango seed kernel meal on growth performance of broiler chicken diet. The study was conducted at the Poultry Unit of Teaching and Research farm at the Department of Animal Health and Production Technology Yobe State College of Agriculture Science and Technology Gujba Damaturu Yobe state. One hundred and fifty day old marshal strain broiler chicken were randomly assigning in to five treatments with three replications of 10 bird each in a completely randomize design the experiment lasted for 8 weeks (56day) the five treatment diet use contains 0% CMSKM, 5%, 10%, 15% and 20% CMSKM to replace maize. Cooked mango seed kernel meal contain 8.01% CP and 3675.5 me , kg/dm dray matter. The parameter recorded in community include daily fed intake, week gain fed conversion ration and mortality. During The entire period daily fed intake was recorded at 125.20, 129.5, 124.68, 133.48, and 131.6 g/bird for T1, T2, T3, T4, and T5 respectively. It show that their was significantly higher (p<0.05) for T4 and compare to T1, T2, T3, and T5 and 15% level of inclusion. The feed conversation ration during the entire period was recorded 2.61, 2.70,2.76, 2.79 and 2.71 respectively and higher in T4 compare to T1, T2, T3 and T5. base on the outcome of this study, indicated that cooked mango seed kernel meal could replace maize up to 15% without compromising effect on the growth performance.