Two hundred and twenty-five day-old broiler chicks of “Anak 2000” strain were used to determine the effect of partially and completely replacing fishmeal (Fm) with lizard meal (Lm) in broiler birds. The objectives were targeted at the growth performance, nutrient digestibility and the cost benefit analysis of the birds from day old to the eight weeks of research. A week was carved out for the brooding of the birds. The birds were distributed into five treatment groups of forty-five birds, replicated three times with fifteen birds each per replicate in a completely randomized design (CRD). The processed lizard meal was included in the diet at levels of 0, 25, 50, 75 and 100% corresponding to treatments 1, 2, 3, 4 and 5. Feed and water were given ad-libitum throughout the experiment. Proximate analysis of lizard meal and the experimental diets were equally carried out according to laid down standards. Results obtained showed that growth performance parameters differed significantly (p<0.05) across the treatment groups with treatment 4 (75% Lm) possessing a superior (p<0.05) value of 2987.33 g, 53.66 g and 2.28 in terms of final body weight (FBW), average daily weight gain (ADWG) and feed conversion ratio (FCR), which was closely followed by birds in treatment 5 (100%) with 2870 g, 51.23 g and 2.40 for FBW, ADWG and FCR. The least performance was obtained in treatment 3 (50%) with 2431.33 g, 42.27 g and 2.93 for FBW, ADWG and FCR respectively. Nutrient digestibility results showed higher values of dry matter, crude protein and ether extract in treatment 4 (81.24%, 63.82% and 52.78%) which also has the least value for crude fiber (44.05%). Cost benefit analysis was best in treatments 4, with profit and cost benefit ratio of ₦1098.97 and 1.58. Thus, from the overall results obtained in the present research work, it can be deduced that replacement levels at 75% performed best, though replacement level up to 100% is viable without any detrimental effect on the performance and cost implication in the short and long run.