Physostigmine and oxotremorine effects on local cerebral glucose utilization (LCGU) in rat brain optic systems were examined by the [14C]2-deoxy-D-glucose procedure. Both drugs significantly stimulated LCGU in the superior colliculus (superficial layer) and nucleus of the optic tract, but not in the visual cortex. Physostigmine, but not oxotremorine, stimulated LCGU in components of the accessory optic system. The effects in the accessory optic system apparently result from nicotinic actions of physostigmine.