We used affinity purified antisera specific for group II metabotropic glutamate receptors in combination with a pre-embedding immunocytochemical method for light microscopy to investigate the localization of mGluR2/3 receptors in the enteric nervous system of the rat small intestine. In the submucosal plexuses of the jejunum and ileum, strongly mGluR2/3 immunoreactive cells were distributed between the circular muscular layer and the muscularis mucosa. In addition, oval or rounded immunostained ganglion cells appeared located in the myenteric plexuses of both intestinal regions. Nerve fibers intensely stained were observed extending between adjacent myenteric ganglia. The localization of mGluR2/3 receptors in enteric neurons might have functional implications in the physiology and pathology of the gut.