A mucocele is a slowly progressive cystic lesion of paranasal sinuses secondary to obstruction of the sinus ostium. It is an extremely rare condition in the pediatrics age group. The symptoms usually result from lesion expansion, inflammation, or compression of the adjacent structures. We report a case of an 11-year-old boy who presented with a right-side ethmoid mucocele with no known etiology and no history of cystic fibrosis. The patient underwent endoscopic sinus surgery for mucocele excision and abscess drainage. Clinicians are recommended to suspect paranasal mucoceles in patients presenting with progressive non-specific headache and orbital manifestations.