Objective: Oral lesions are among the important reasons for seeking dental care. Being frequently encountered, giant cell lesions form an important group of oral lesions. The epidemiologic data on these lesions, however, is scarce in Iran. The present study investigatedepidemiological and demographic characteristics of giant cell lesions in oral biopsies done in one of the largest oral pathology departments in Iran.Materials and Methods: This descriptive survey studied the existing biopsy records of 2265 patients referred to the Department of Oral Pathology in Shahid Beheshti Dental School from 1991 to 2002. Records with final diagnosis of giant cell lesion were identified.Data on type of lesion, distribution of lesions, the involved jaw, and patients' gender and age was extracted from these records.Results: In total, 144 giant cell lesions were identified. These lesions comprised peripheral giant cell granuloma (59.5%), central giant cell granuloma (36.6%), cherubism (2.5%),and aneurysmal bone cyst (1.4%). Most of the cases had been occurred among women(54.9%), in their second and third decades of life (49.4%). The anterior region of the mandible was the most common location of these lesions (26.2%). In approximately half of the cases, the first clinical diagnosis was similar to the histopathologic diagnosis.Conclusion: The giant cell lesions were more common in women and in the anterior region of the mandible. More commonly, they occurred in the second and third decades of life unilaterally. This study elucidates the epidemiologic data of giant cell lesions in Iranand the results can be helpful for dental scholars in various fields.