To investigate the distribution of nitrergic and cholinergic innervation in rabbit, pig, and human upper urinary tract, (UUT) whole-mount preparations and frozen sections were stained with nicotinamide adenine dinucleotide phosphate (NADPH)-diaphorase and acetylcholinesterase (AChE) histochemistry. NADPH-diaphorase and AChE staining demonstrated two neuronal plexuses in the submucous and muscular layer of the UUT in all three species. The presence of nitrergic and cholinergic neuronal networks in the normal UUT suggests that autonomic innervation may play an important role in the transmission of ureteral peristalsis.