Pituitary apoplexy is an acute infarction of pituitary gland, and potentially life-threatening condition that may be highly variable in its clinical presentation. We report a 54-year-old man presenting to the emergency department with an isolated oculomotor nerve palsy. Computed tomography (CT) scan revealed an isodense mass within sellar region and subsequently, magnetic resonance imaging (MRI) revealed a pituitary apoplexy causing a compression of right oculomotor nerve. The patient received hydrocortisone immediately, and did well with medical management. An isolated oculomotor nerve palsy is very rarely the presenting sign of pituitary apoplexy. When correctly diagnosed and treated, the third nerve palsy appears to be reversible. A pathophysiology, differential diagnosis, and treatment is described.