Isolated orbital mucocele without connection between the mass and paranasal sinuses is extremely rare and poorly understood. A 66-year-old female patient with diplopia, right extra-orcular mobility limitation and right eyelid swelling without any nasal symptoms, and normal nasoendoscopic finding. Computed tomography and magnetic resonance imaging revealed a right intraorbital cystic mass lesion. Endoscopic sinus surgery with marsupialization was performed, and an orbital mucocele was confirmed on histopathology. We present this case with a brief review of the literature.