Throughout pregnancy and lactation rats were given diets with 22 or 8% protein and their offspring continued on the same diets to 60 days old when they were killed. Weight and length of the intestine differed significantly between the groups and were 229.52 g and 114.60 cm for the controls and 40.46 g and 62.80 cm for those deprived of protein. Average number of myenteric neurons per cm² of ileum was 69 249 for controls and 74 189 for those deprived of protein. Incidence of small, medium-sized and large neurons did not depend on nutritional state. In the group deprived of protein the intestinal wall was altered, especially with regard to height, number and shaped of the intestinal villi.