BACKGROUND: Ocular flutter is a rare horizontal eye movement disorder characterized by rapid saccadic oscillations. Excessive discharge of burst neurons, and/or loss of tonic excitation of pause cells cause ocular flutter in several neurologic diseases. Ocular flutter can be easily differentiated from other saccadic oscillations with the aid of electro-oculography (EOG) findings showing an absence of intersaccadic intervals. METHODS: We analyzed EOG findings of ocular flutter in four patients. RESULTS: Ocular flutter, which was shown as rapid, repetitive, horizontal, symmetrical, and sinusoidal movements without intersaccadic intervals on EOG, was confirmed in four patients. The etiology of each patient was olivopontocerebellar atrophy (1 case), meningoencephalitis (2 cases), and lithium intoxication (1 case). CONCLUSIONS: Ocular flutter can be present in numerous neurologic diseases. Characteristic EOG findings are useful in the diagnosis of ocular flutter.