Secretory otitis media is the most common middle ear disease of childhood. It heals spontaneously, by medical therapy or by minor surgical procedures in most of the cases. Sequelae such as retraction pockets and adhesive otitis that lead to cholesteatoma rarely occur, but initialy it is hard to diagnose which patient will acquire a sequela. It is well known that mastoid pneumatization is poor in the patients who had complications like retraction pocket, adhesive otitis and cholesterol granuloma. The aim of this study was to determine if any relationship exists between mastoid pneumatization and secretory otitis media. Lateral mastoid X-rays of 47 children with secretory otitis media were evaluated. After 2 months of follow-up with medical therapy, 30 of the 47 patients needed ventilation tube insertion. The remaining 17 patients showed total recovery with medicines only. Control X-rays of the operated patients were taken 6 months after the operation. Mastoid pneumatizations of patients healed with medicine were compared with the operated patients. There were statistically significant differences between the mastoid pneumatizations of surgically and medically treated groups. In addition we observed a statistically significant difference between the mastoid areas of the preoperative and the postoperative X-rays. We concluded that mastoid pneumatization might be considered as a prognostic indicator in secretory otitis media. The estimated prognosis is poor when the mastoid pneumatization is poor. (C) 1997 Elsevier Science Ireland Ltd.