A 10-year-old boy presented with a complaint of a left-sided nasal obstruction with an associated foul-smelling discharge. Physical examination and anterior rhinoscopy revealed that a whitish, friable mass had completely filled the left nasal cavity. On computed tomography, a soft-tissue mass was seen filling the cavity and extending to the paranasal sinuses with bone erosion. A biopsy of the mass suggested that it represented a cholesteatoma. The lesion was removed via nasal endoscopy, and histopathology confirmed the diagnosis of a cholesteatoma. No recurrence was noted during 6 months of follow-up. Cholesteatoma of the paranasal sinuses is a rare entity, as only a few dozen cases have been reported in the literature.