Cholesteatoma in children may be a sequel to chronic exudative otitis media with tympanic membrane retraction but he the role of grommets in the possible facilitation of squamous epithelial invasion into the middle ear is not yet clear. A retrospective study was made of the history and prior treatment in 25 children who underwent mastoidectomy for cholesteatoma at St. Mary's Hospital between 1975 and 1986. Thirteen patients had undergone previous middle ear aeration procedures which included myringotomy, cortical mastoidectomy and grommets. There was no difference in the site or severity of cholesteatoma in the operated and non-operated cases. Of the seven patients with a history of multiple grommets three had primarily attic, and three had primarily mesotympanic disease. The latter had greater ossicular erosion. One patient with an intact tympanic membrane had grommet insertion subsequently developed a cholesteatoma. While cholesteatoma due directly to the presence of grommets is rare, it appears that children who require multiple grommet insertions constitute a high risk group and should be very closely monitored.