OBJECTIVE: To tell to case of mucoceles of etmoidal sinus to the right in patient taken care of in the Service of Otolaryngology and Surgery of Cervical-Face of the Regional Hospital of President Prudente in the period of July to August of 2011. CASE REPORT: M. H. P., 55 years, feminine sex, medium brown, look the service with chronic headache complaints to retro-ocular intermittent associate to the intermittent bulging of right ocular globe and nasal blockage has 3 years, without worsening factors or improves. To the physical examination: bulging of right eye, previous rhinoscopy without alterations. Carried through computerized cat scan of sinus of the face evidencing mucous thickening of the sphenoid sinus and the maxillary sinus, with partial veiling and hydro-aereal level in the left maxillary sinus, associate the material hypodense that total obliterated the frontal sinus to the right and the etmoidal cell previous ipsi-lateral, with thinning of the papyraceous blade of the same side, with light compressive effect on the medial straight muscle. Not demonstrated to resorption or osseous remodeling. Carried through front-etmoidal sinusotomy endoscopic via, with resection of mucoceles frontal and right ethmoidectomy. It was presented asymptomatic in the return consultations. CONCLUSION: Mucoceles of etmoidal sinus is an injury benign of low frequency if compared with others mucoceles, but of great importance in function of the anatomical localization for the damage possibility the important periocular structures. The precocious diagnosis is basic to prevent preventable sequels when treated adequately.