This retrospective study was conducted to determine the prevalence of nasopharyngeal angiofibroma according to age, stage, clinical signs and average blood transfusion during surgery in educational hospitals affiliated to Isfahan University of Medical Sciences.Background:This retrospective study was conducted on 250 records of patients suffering from angiofibroma and hospitalized from 1988 to 2003 in Al-zahra and Ayatollah Kashani hospitals, affiliated to Isfahan University of Medical Sciences.Methods:All cases were male, and the mean age was 16 years with a range of 7 to 41; the highest prevalence was found in the 11-20-year-age group. The most frequent sign was epistaxis (80%) and nasal obstruction (70%). The average volume of blood transfusion during the surgery was 4-5 units. The most frequent stage at the time of diagnosis was IIB and IIC (complete invasion of petrygomandibular fossa and protrusion to infratemporal fossa) and the rarest stage was IA and IIA according to Session classification.Findings:Angiofibroma is a rare tumor; however it is the most frequent nasopharyngeal tumor in young adults. Although it has benign histology, but can have important side effects. Its early diagnosis and treatment can prevent its side effects and may facilitate the surgery; hence it should be considered in the differential diagnosis of nasopharyngeal disorders.Conclusion:Angiofibroma, nasopharyngeal mass, prevalence-clinical signs and symptomsKey words