An experiment was conducted to study the performance of broilers on twelve diets containing different levels of single super phosphate (SSP) replacing dicalcium phosphate (DCP) with and without ionophor (maduramycin). Diets used were isonitrogenous containing 22% and 20% CP in starting and finishing broilers, respectively along with 2800 Kcal ME/kg. In diets 1 to 6, DCP was replaced by SSP at graded levels (0%, T ; 20%, T ; 1 2 40%, T ; 60%, T ; 80%, T and 100%, T ). In diets T to T DCP was replaced by SSP as in T to T but these diets were 3 4 5 6 7 12 1 6 supplemented with maduramycin as ionophore to see their effect on nutrient utilization. During 1st to 4th weeks, maximum body weight attained by the broilers allotted 40% SSP diet without ionophore was statistically comparable to those assigned 100% DCP as well as 60% SSP diets. The feed intake increased (P<0.05) in broilers assigned diets containing SSP up to 60% level without ionophore but further increase in SSP reduced it significantly. Best feed efficiency ratio (FER) was noted in broilers allotted 40% SSP diet. While, with ionophore, best FER noted in broilers allotted T diet was comparable with those allotted T and T diets. The Performance Index (PI) was maximum and 7 8 9 significantly (P<0.05) higher in broilers allotted T diet. During 5th to 6th weeks period, maximum weight gained by the 3 broilers assigned T3 diet was statistically similar to those allotted T and T diets. Overall, performance of broilers for 1 2 0-6th weeks, revealed that use of SSP up to 60% of DCP either improved the weight gain or had no significant influence on it. Addition of ionophore increased the weight gain only in broilers allotted control or 20% SSP diet. Maximum feed intake was observed in groups assigned 20% SSP diet. Use of ionophore increased the feed intake significantly in control as well as in those allotted 40% SSP diet. Best FER was observed in broilers allotted control diet without ionophore, but with ionophore use of 60% SSP instead of DCP was responsible for significantly higher FER. Maximum PI observed in broilers allotted control diet with and without ionophore was statistically similar to those allotted 40% SSP diet without ionophore. Hence it is concluded that use of 40% SSP instead of DCP in the mineral mixture of broilers is economical and it would be uneconomical to use ionophore under cage system of rearing of broilers.