Mucoceles are mucus-containing cysts lined by epithelium. Although benign, they may show expansive growth and remain undiagnosed until symptoms due to compression of surrounding structures arise. We report a rare case of frontoethmoid mucocele with intracranial extension in an 80-year-old woman with complaints of headache, right diplopia and proptosis. A right frontoorbital craniotomy was performed, and a mucocele in the frontal sinus extending into the frontal lobe and orbit was totally removed. The patient was successfully treated without any complication. The two-year follow-up results were satisfactory. Magnetic resonance imaging excluded any recurrence of the mucocele. Combined intranasal and transcranial approach is necessary to treat giant frontoetmoid mucoceles with intracranial extension.