This study aimed to establish phytochemical composition and determining the effect of Capsicum frutescens powder on body weight and carcass yield of Cobb500 broilers. Four hundred and fifty broilers at 35 days were randomly assigned to treatments defined by three dietary inclusion levels (1.1, 2.2, 4.4%) of C. frutescens powder for each of the three durations (13 days, 19 days, 24 days) prior to 59 days of age. A control group received only the basal finisher diet. Each treatment group had 15 birds replicated thrice. The phytochemicals detected in C. frutescens powder included flavonoids, phenols (588 mg GAE/100g), alkaloids (6.8%), and saponins (23.5%). Further, only diets formulated with 2.2% inclusion level and provided for 19 days increased body weight (1258g, p=0.03), carcass weight (786g, p=0.03) by 14 and 15% respectively relative to the control. The results of this study highlight that C. frutescens has several beneficial phytochemicals for improving broiler production and that an inclusion level of 2.2% in finisher diets for 19 days is acceptable since it has capacity to improve body weight and carcass yield of Cobb500 broilers.