Reports on the incidence of odontogenic tumours are infrequent with only a limited number of series having appeared in the literature. In this paper, the results of a multicentre retrospective study on the histologic types and relative frequencies of odontogenic tumours in Turkey are presented. The results indicated that the most frequent histologic type was ameloblastoma (36.5 per cent) and the area at greatest risk for the development of odontogenic tumours was the mandibular molar region. A Table showing the most likely type of tumour by location is also presented.