A research study was conducted to evaluate the effect of Saccharomyces cerevisiae cell walls (ScCw) at 500 g/t and avilamycin as a growth promoter antibiotic(GPA), at 10 ppm, in sorghum + soybean meal diets for broiler chicks, on live production perfor- mance at 21 days of age, as well as on length, width, number and area of intestinal villi at 10 and 21 days. A total of 200 one-day- old broiler chicks were allocated in batteries and distributed in a completely randomized design, consisting of a 2 × 2 factorial arrangement with fi ve repetitions of 10 birds each one. The factors were the presence and absence of ScCw and GPA for the pro- ductive variables. The intestinal villi data were analyzed as a completely randomized design with repeated measurements at ten or 21 days of age. Results of productive variables showed differences (P < 0.05) in body weight (660 vs 683 g) and feed conversion (1.47 vs 1.41 g/g), in favor of birds that consumed the diet with GPA. The addition of ScCw improved (P < 0.05) body weight (662 vs 681 g). The greater the age of birds (21 vs 10 days), the greater (P < 0.05) the width (264 vs 398 μ ), number (41.7 vs 45.2 n) and area (26.2 vs 44.5 103 μ2 ) of intestinal villi; the effect of ScCw was manifested at 21 days with a larger area of villi. This partly explains the benefi cial effect of these natural products on broiler production.