OBJECTIVE: The aim of this study was to assess the prevalence of hypodontia and hyperdontia among a group of orthodontic patients. MATERIALS AND METHODS: This cross sectional study was conducted using radiographs of 4256 patients (2032 males and 2224 females) who attended the Department of Orthodontics, School of Dental Medicine, University of Sarajevo. Radiographs were examined for the prevalence of hypodontia and hyperdontia in permanent dentition. Hypodontia was recorded when a tooth was absent on the panoramic radiograph and hyperdontia was recorded as an increased number of teeth above that described by normal dental formula. All data were analyzed using descriptive statistics including frequency and percentage, and differences between groups were tested using the χ2 test, or Fisher exact test. RESULTS: In the sample of orthodontic patients, 4.08% subjects had a least one dental anomaly, hypodontia or hyperdontia. The observed prevalence of hypodontia was in 3.42% subjects, and it was more prevalent in females than in male subjects. The observed prevalence of hyperdontia was in 0.65% subjects and hyperdontia was more common in males than female subjects. CONCLUSIONS: By early diagnosis of a reduced or increased number of teeth, various modes of therapy with a multidisciplinary approach may be performed to correct the aesthetic and functional problems caused by hypodontia or hyperdontia.