A 63-year-old female complained of left frontal headache and swelling for several months. Physical examination revealed left supraorbital soft, nontender, nonpulsatile mass without bruit. The left eye was displaced downward with respect to the normal right globe. Based on the clinical and radiological findings, the patient was diagnosed as a mucocele arising from the left frontal sinus. The patient underwent a transcranial approach through coronal incision. In this patient, large portions of the anterior and posterior frontal sinus walls were destroyed in association with epidural spread, so we performed cranialization of the frontal sinus and removed the mucosal wall with the aid of a microscope. With a brief review we present a patient with mucocele of the frontal sinus extending into the intracranial and intraorbital region, which was successfully treated by a transcranial approach.