The trial was conducted for a period of 35 days to assess the comparative efficacy of Lysure-H (Lys-H) and synthetic lysine (L-Lysine HCL 98.5%) on the growth performance and cost benefits in broiler chickens. A total of180-day-old Arbor-Acre Plus breed of broiler chicks were assigned to three (3) dietary treatments, each replicated six (6) times with ten (10) chicks per replicate in a Completely Randomized Design. Diet I (Control) had 100%L-Lysine HCL 98.5% and 0%Lys-H, Diet II (50%L-Lysine HCL 98.5% and 50%Lys-H), and Diet III (0%L-Lysine HCL 98.5% and 100%Lys-H). At the end of the trial, two (2) birds per replicate were slaughtered for their carcass yield and relative organ measurement. All data collected were subjected to analysis of variance. The results shows that all the growth performance parameters, final weight, weight gain, feed intake, and feed conversion ratio were not significantly (P>0.05) influenced by the dietary treatments. For the carcass characteristics, only the breast muscle was significantly (P0.05) influenced by the dietary treatments. The cost per kg of feed varied between N639.00 andN656.00, with the highest recorded in diet I. Based on the results obtained in this trial, it could therefore be concluded that the inclusion levels of 50%L-Lysine HCL 98.5% + 50%Lys-H (Diet II), and 100%Lys-H (Diet III) supported the bird performance in terms of growth, carcass yield, organ weight, and also led to a reduction in feed cost per 1kg feed as the levels of the Lys-H increased.