The study was carried out to assess the incidence of radiolucent lesions in the mandible in a sample of Egyptian patients. 160 cases were collected from Oral Surgery Department, Faculty of Oral and Dental Medicine, Cairo University and other public hospitals. (68.75%) of patients had cysts, (20%) had odontogenic tumors and (11.25%) had cyst-like lesions. In cyst group, periapical cysts were (67 %), dentigerous cyst (15.5%), keratocyst (11.8%) and residual cyst (5.5%). In odontogenic tumors group, ameloblastoma comprised (78%).In cyst-like lesions group, central giant cell granuloma was the most prevalent type.