Abstract: The relative efficacy of five proprietary vitamin-mineral premixes on performance and carcass characteristics of broiler chickens was undertaken in a trial lasting six weeks at the Teaching and Research Farm, University of Ibadan, Ibadan, Nigeria. A total of two hundred and eighty eight 1-day broiler chicks of Abor acre strain were randomly allotted to six dietary treatments of forty eight chicks per treatment. Each treatment was a triplicate of sixteen chicks per replicate. Six isocaloric and isonitrogenous diets were formulated. Diet 1 (T1) was the control without any premix. Other diets were supplemented appropriately with 0.25% Daramvita (T2), Biorganics (T3), Hinutrients (T4), Optimix (T5) and DSM Nutripoults (T6). The experimental diets were offered to the respective birds with water given ad libitum. The design of the experiment was a completely randomized design. The feed conversion ratio of birds on T3, T4, T5 and T6 were 2.64, 2.58, 2.61 and 2.57 respectively and were significantly different (p<0.05) from those on T1 (3.62) and T2 (3.35). The obtained live, bled and defeathered weights and dressing percentage values of broilers varied significantly (p<0.05) with the type of vitamin-mineral premix used while values of other primal cuts were statistically similar (p>0.05). Performance and carcass indices indicated variable potency and efficacy of the evaluated proprietary vitamin-mineral premixes in Ibadan, Nigeria.