The histopathological changes in the ciliary ganglia due to subarachnoid hemorrhage were investigated. Subarachnoid hemorrhage was produced by infusing autologous blood to the cisterna magna of rabbits. The number of neurons in the ganglia was evaluated with physical dissector method. Comparing with controls, a statistically significant increase in the number of degenerated neurons in subarachnoid hemorrhage group was noted. It is considered that the loss of trophic effect from the presynaptic supply of ciliary ganglion via the preganglionic fibers of oculomotor nerve could alter the structure of the ganglion through the anterograde transneuronal degeneration process in subarachnoid hemorrhage.