Aspects of growth performance and nutrient retention of starter broilers fed diets containing 10% boiled Mucuna cochinchinensis meal with graded levels of methionine supplementation (0, 0.25, 0.5 and 0.75%) were assessed using 120 unsexed ‘Anak’ strain day-old broiler chicks. The birds were randomly assigned to the four dietary treatments and each treatment was replicated three times with 10 birds per replicate. The experiment lasted 5 weeks, with three birds selected from each replicate and used for nutrient retention studies at the beginning of the fifth week. The 0.75% methionine supplement group had the highest (P < 0.05) daily feed intake and final liveweight. The 0.25% methionine supplement group had the best (P < 0.05) feed conversion ratio and net protein utilisation and the second best final liveweight. The mean dry matter, crude protein, ether extract and nitrogen-free extract retention and energy utilisation for birds fed diets supplemented with methionine at 0.25, 0.5 and 0.75% were similar but significantly higher (P < 0.05) than those of birds fed the unsupplemented diet. Based on efficiency of utilisation of the diets and projected economics of production, the 0.25% level of methionine supplementation appears to be ideal for use in 10% boiled M. cochinchinensis-based diets for starter broiler chicks.