Objective: To present an alternative surgical option for frontal sinus osteoma.
Material and Method: A woman presented with a symptomatic large osteoma in right frontal sinus. Two-hole trephination was planned to remove the osteoma using nasal endoscope and a drill in each hole.
Results: The osteoma was drilled and removed transnasally. Two months later, two small fragments of osteoma were detected remaining in the lateral aspect of the sinus. The fragments were removed successfully with the same technique. The patient was asymptomatic six months postoperatively.
Conclusion: Two-hole trephination technique or Muntarbhorn technique is an attractive option for frontal sinus osteoma.

Keywords: Osteoma, Paranasal sinus neoplasms, Frontal sinus