Eighty piglets aged 14, 28, 35 and 56 days -weaned at day 28 -were subjected to this investigation. Each age-group consisted of five animals which were fed an Enterococcus faecium NCIMB 10415 (Cylactin ) and Bacillus cereus var. toyoi (Toyocerin ) based diet. Five animals served as controls. Tissue samples were collected immediately after sacrifice at 8.30 h a.m. from duodenum, jejunum, ileum, cecum and colon to examine intestinal morphology and histochemistry. The results showed that with respect to villus height and crypt depth supplementation of probiotics in piglets feed seemed to influence the morphology and enlargement factor not at all or only to a certain extent. With respect to the number of goblet cells, the difference between probiotic fed animals and control animals was generally extremely low. The shape of the villi of the small intestinal segments greatly varied in all age groups of control and probiotic fed animals. However, this morphological variety does not depend on the mode of feeding.