The purpose of this study was to verify the effects of proteic undernutrition on the neurons of the myenteric plexus from the duodenum of Wistar rats. Twenty-four animals at the age of 60 days were divided in four groups, which were named according to the period their mothers received hypoproteic ration (8%). Some segments of duodenum were subjected to histological treatment and stained with hematoxilin-eosin and some were used for whole mount preparations stained with Giemsa. We observed small, medium-sized and large neurons grouped in ganglia of various shapes. It was concluded that the maternal proteic undernutrition does not affect the organization of the myenteric plexus and that animals submitted to undernutrition during gestation and lactation, when normally fed, show neurons with strongly basophilic cytoplasm and larger cellular bodies than those from control animals.