The aim of the present experiment was to determine the influence of either probiotic or antibiotic inclusion in the diets of pigs from birth on the development of enzyme activity in the small intestine. Pigs were fed on creep feed and grower diets containing either a probiotic, an antibiotic or no added growth promoter. At 7, 17, 42 and 80 d of age pigs from each treatment group were sampled to investigate the development of carbohydrase and peptidase activity in the mucosa at five sites along the small intestine. Inclusion of either the probiotic or antibiotic had a significant effect on the development of sucrase (sucrose α-D-glucohydrolase; EC 220.127.116.11), lactase (β-D-galactoside galactohydrolase; EC 18.104.22.168) and tripeptidase (EC 22.214.171.124) activities before weaning but had no effect on depeptidase (EC 126.96.36.199) activity. The study of the distribution of enzyme activity along the small intestine showed significant differences between the proximal and distal sections associated with weaning.