The formation of symptomatic intradural mucocele associated with a paranasal osteoma is rare, and no standard treatment has been established. Here, we present a case of intradural mucocele in a 27-year-old man complaining of headache and generalized convulsion. Cranial CT and brain MRI showed a left frontoethmoidal osteoma extending into the left anterior cranial fossa and orbit along with a mass in the left frontal lobe. He underwent resection of both intracranial osteomas and the mass through left frontal craniotomy. Histological findings were consistent with a mucocele, and the diagnosis of an intradural mucocele associated with a frontoethmoidal osteoma was confirmed. The postoperative course was uneventful. Although both osteoma and mucocele are benign, they may cause life-threatening symptoms by expanding intracranially. A tailored treatment considering the invasiveness and postoperative long-term follow-up of the patient is essential for this uncommon condition.