This study was conducted to determine the effects of raw and cooked jackfruit seed meal (JSM) as a substitute on the growth performance of broiler chickens. One hundred eighty (180) broilers were subjected to a two factorial experiment and were distributed into six (6) treatments (A1B1 - control, 100% commercial feeds; A2B2 -5% raw JSM and 95% commercial feeds; A2B3 -10% raw JSM and 90% commercial feeds; A2B1 - control, 100% commercial feeds; A2B2 - 5% cooked JSM and 95% commercial feeds; and A2B3 - 10% cooked JSM and 90% commercial feeds) following a complete randomized design (CRD). Each dietary treatment was replicated thrice with 10 broilers per replication. Results showed significant differences in the growth performance of the broilers in terms of the final weight, gain in weight, average daily gain, and feed conversion ratio. However, data revealed that there is no significant difference between the inclusion of raw and cooked jackfruit seed meal in the growth performance of the broilers. In conclusion, the use of jackfruit seed as a substitute in the diet of Cobb 500 broilers at 10% level of inclusion (B3) has generally depressed their growth performance. Hence, jackfruit seed meal at 5% level of inclusion was gleaned as a potential feed substitute in the diet of the broilers. Key words: jackfruit seed meal, growth performance and broiler chickens.