This study was designed to determine the intestinal characteristics and nutrient retention of broiler chickens subjected to different protein regimes supplemented with betaine. Four experimental diets were formulated, consisting of two basal diets containing 20% and 23% crude protein (CP), both with and without betaine supplementation at the level of 0.14%. The diets were applied to 180 broiler chickens that were randomly allotted to 2×2 factorial arrangement with five replicates of nine chickens each. The diet with 20.0% CP generated better small intestine characteristics than the diet with 23.0% CP as indicated by the longer ileum and total small intestine length (P