Monocular enucleation induced changes in the visual system in neonates have been reported by many workers but information regarding its effects in adults remains scanty. Present study is an attempt to find out the latter in rabbits. 25 adult rabbits of either sex were subjected to monocular enucleation under general anaesthesia. A similar number of nonenucleates served as controls. Animals were sacrificed after post lesion-survival periods ranging from 2 weeks to 4 months. Brains were fixed by trans-cardiac perfusion of 10% formalin. Superior colliculi were removed from midbrain and processed for paraffin embedding. 10 μ thick sections were stained with Hae-matoxylin and Eosin, Cresyl violet and Luxol fast blue and Thionin as well as Kluver Barrera and Glees and Marshland stains. To access the deafferentation-induced changes in the contralateral (with respect to enucleation), sections from superior colliculi were observed under light micro-scope. Morphological changes were in the form of vacuolation in the neuropil, fascicular disor-ganization and fragmentation of myelin, cytoplasmic and nuclear disintegration of neurons and glial cell aggregation. It was concluded that though the deafferentation-induced changes were not dramatic at any point of time during study, yet its extent could be correlated with duration of post-experimental survival period of the animal.