This study was carried out to clarify the neuronal organization in pineal body of catfish. The pineal body was observed by acetylcholinesterase histochemistry and electron microscopy. The neuronal types observed in the pineal body of catfish were bipolar and multipolar cells. Multipolar cells were found throughout the pineal end vesicle and whole stalk, but bipolar cells only in the end vesicle and distal stalk. The pineal tract was formed by the long axons of these neurons. The neuronal clusters(pineal ganglia) were also observed in the end vesicle. In summary, the type of neurons in catfish pineal was different from that of other species, and the neuronal distribution differed depending on the region of pineal body. These results reflect the interspecific and regional differences of the pineal organization of fishes.