Fungus ball (FB) is a non invasive form of fungal sinusitis that generally affects immunocompetent subjects. Isolated involvement of the frontal sinus is extremely rare. The treatment is surgical. Previously, it was based on the external approach. Recently, the endoscopic approach has been increasingly employed.

We report three cases of frontal sinus fungus ball. Two patients underwent endoscopic endonasal frontal Draf type IIb sinusotomy with complete removal of the pathologic material. The third patient had an external approach due to the extensive pneumatisation of the frontal sinus, the defect in its floor and the orbital involvement. There were no intraoperative or postoperative complications. No recurrence of the disease was observed during the three, two and twelve months’ follow up period, respectively.

Correct clinical and radiological diagnosis of isolated frontal sinus FB still remains a challenge. Endoscopic sinus surgery with endonasal Draf type IIb or type III frontal sinusotomy is effective for the treatment of frontal sinus FB. It is the treatment of choice and replaces the traditional external approaches.