Mucoceles are secreting cysts lined by sinus mucous membrane and enlarged by an accumulation of the products of secretion and desquamation. They occur in relation to the blockage of the natural sinus ostium. The mucoceles are most frequently found in the frontal sinus, but are also found in the other paranasal sinuses. The authers experienced a case of large frontal sinus mucocele with exposed dura. The case was treated with anterior osteoplastic operation and abdominal fat tissue obliteration. The patient's prognosis was excellent, no recurrence evidence, no abnormality. So, we present this case with a brief review of the literature.