NADPH-diaphorase histochemistry selectively stains discrete populations of retinal interneurons in diverse mammals, including two amacrine types in the rabbit retina. In this study, we have demonstrated that most of these neurons show GABA-like immunoreactivity by combining indirect immunofluorescence and diaphorase histochemistry on frozen retinal sections. The NADPH-diaphorase amacrines account for only a small proportion of the GABA-positive cells in rabbit retina, thus reinforcing the emerging consensus that GABAergic amacrines are remarkably diverse in their morphology and function.