<p>The objective of the present study was to determine the effects of dietary supplementation of graded levels of coffee by-products (CBP) on growth performance, gut health, and toxicity in broiler chickens. A total of 60 (14 days old) Cobb 500 broiler chickens were used in this experimental study. The three treatment diets were prepared with 0%, 1.5% and 2.5% CBP in a complete randomized experiment. There were no differences in total feed intake (TFI) across treatments (<i>P</i> &gt; 0.05). However, chickens fed diets with 2.5% CBP had lower total weight gain (TWG) and higher feed conversion ratio (FCR) compared to those on the control and 1.5% CBP diet (<i>P</i> &lt; 0.05). High digestibility coefficient values for dry matter (DM), crude protein (CP) and crude fibre (CF) were observed in chickens fed control diets compared to chickens fed diets with 1.5% and 2.5% CBP (<i>P</i> &lt; 0.05). Broilers fed diets with 1.5% CBP diets had higher dressing percentages and relative weights for breast than those on the control diet (<i>P</i> &lt; 0.05). Hepatic cells and sinusoidal morphological arrangement were normal across all treatments. Additionally, broilers fed 2.5% CBP exhibited longer intestinal villi compared to those on the control diet. It can, therefore, be said that optimal performance can be attained by incorporating 1.5% CBP in broiler diets without any detrimental effects.</p>