Single retinal ganglion cells projecting bilaterally to the superior colliculi (SC) by way of axon collaterals were revealed in the Japanese monkey (Macaca fuscata). After injecting Fast blue into the SC on one side and Diamidino yellow into the SC on the opposite side, some retinal ganglion cells were double-labeled with both tracers. Most of them were large cells (more than 25 microns in diameter), and were localized in a narrow strip around the vertical meridian of the retina on each side. This retinal area roughly corresponds to the reported strip of nasotemporal overlap, where both crossed and uncrossed retinofugal projections arise.