Objective: To describe a unique idiopathic disorder characterized by transient repetitive unilateral oculomotor pareses. Design: Retrospective observational case series. Participants: Three women presenting for tertiary neuro-ophthalmologic evaluation. Methods: Review of patient records. Main Outcome Measures: Historical information, clinical examination, neuroimaging, and laboratory evaluation for myasthenia gravis. Results: Three 44- to 69-year-old women had recurrent unilateral ptosis over the course of 2 to 4 years. Two had concurrent diplopia with ipsilateral limitation of adduction, and 2 also had a large poorly reactive pupil in the involved eye during the episodes. The attacks lasted between 30 seconds and 4 hours and occurred up to 6 times daily. None of the patients were migraineurs, nor had they received radiation therapy. Neuro-ophthalmologically normal between episodes, all patients had normal magnetic resonance imaging/angiography and testing for myasthenia gravis. Conclusion: Transient, recurrent, unilateral oculomotor nerve palsies may occur spontaneously in healthy individuals. The pathogenesis remains obscure, but the multiple recurrences without evident sequelae and the failure to develop any systemic or neurological disorder suggest that this phenomenon is not indicative of a serious underlying disorder.