This study was conducted to assess the effect of Moringa oleifera leaf meal (MOLM) and Senna occidentalis leaf meal (SOLM) composite mixture on the growth performance, nutrient digestibility, costs and returns of broiler chickens. One hundred and fifty (150) day-old Cobb broiler chicks were randomly allotted to five (5) treatment groups (T1, T2, T3 ,T4 and T5) in a completely randomized design (CRD). Each treatment group contained three (3) replicates with ten (10) birds per replicate and the feeding trial lasted for 8 weeks (56days). The experimental treatment included the control (maize – soya bean meal basal diet with oxytetracyline administered to the birds through drinking water) as T1, T2 (same basal diet was mixed with 0.5% MOLM + 2.0% SOLM), T3 (same basal diet was added with 1.0% MOLM + 1.5% SOLM), T4 (same basal diet was added with 1.5% MOLM + 1.0% SOLM) and T5 (same basal diet was mixed with 2.0% MOLM + 0.5% SOLM). There was no effect of treatments on the live weight, daily weight gain and feed intake, feed conversion ratio (FCR) and protein efficiency ratio (PER) of broiler chickens at the starter phase. At the finisher phase, live weight, daily weight gain and feed intake, feed conversion ratio (FCR) and protein efficiency ratio (PER) were better in broiler chickens that had 1.5% MOLM + 1.0% SOLM (T4) compared to other treatments. Apparent  digestible dry matter, crude protein, crude fibre, ash, ether extract and nitrogen free extract (NFE) of broiler chickens were better in MOLM and SOLM mixture than those on the control. The cost incurred per kilogramme weight gain, total cost of production, income and net profit were lower in birds on MOLM and SOLM blend compared to those on the control group. Conclusively, the combination of Moringa oleifera and Senna occidentalis leaf meal was beneficial in improving the growth performance, nutrient utilization and economic value of broiler chickens. Key words: economic value, growth promoters, oxytetracycline, phytobiotics