Aim of the study was to verify the effects of butyric acid glycerides, as a supplemental ingredient in the diet, on live performance of broiler chickens and on the morphology of their small intestine, since short chain fatty acids are known as selective protection factors against intestinal microbial parasites, potent growth promoters of the gut wall tissues, also in terms of immune modulation response. An experiment was carried out on 150 Ross 308 female chickens, allotted to 5 treatments, over a 35 d ays period: the control, with soybean oil as the energy supplement, and 4 treatments with increasing amounts (0.2, 0.35, 0.5, 1% mixed feed) of a mixture of butyric acid glycerides (mono-, di- and tri-glycerides). Treated animals showed a higher live weight at slaughtering (P<0.05) with a better feed conversion rate. The carcase characteristics were not influenced, but the small intestine wall resulted slightly modified with shorter villi, longer microvilli (P<0.01) and larger crypts depth in jejunum (P<0.01), only with lowest concentration of the supplement (0.2%). It is concluded that butyric acid glycerides are an efficient supplement to broilers' diets, deserving particular attention as a possible alternative to antimicrobial drugs, which have been banned in Europe.