This article provides an overview of the imaging findings of diseases affecting the optic nerve with special emphasis on clinical-radiological correlation and on the latest technical developments in MR imaging and CT. The review deals with congenital malformations, tumors, toxic/nutritional and degenerative entities, inflammatory and infectious diseases, compressive neuropathy, vascular conditions and trauma involving the optic nerve from its ocular segment to the chiasm. The implications of imaging findings on patient management and outcome and the importance of performing high-resolution tailored examinations adapted to the clinical situation are discussed.