To gain more insight into the prevalence of dental agenesis. Data from Caucasian populations in North America, Australia and Europe were included in a meta-analysis. For the prevalence of African American, Chinese and Arab groups only indications could be reported because of a limited number of studies. Agenesis differs by continent and gender: the prevalence for both sexes was higher in Europe (males 4.6%; females 6.3%) and Australia (males 5.5%; females 7.6%) than for North American Caucasians (males 3.2%; females 4.6%). In addition, the prevalence of dental agenesis in females was 1.37 times higher than in males. The mandibular second premolar was the most affected tooth, followed by the maxillary lateral incisor and the maxillary second premolar. The occurrence of dental agenesis was divided into three main groups: common (P2(i) > I2(s) > P2(s)), less common (I1(i) > I2(i) & P1(s) > C(s) & M2(i)) and rare (M2(s) & M1(s) > C(i) > M1(i) & I1(s)). Unilateral occurrence of dental agenesis is more common than bilateral occurrence. However, bilateral agenesis of maxillary lateral incisors is more common than unilateral agenesis. The overall prevalence of agenesis in the maxilla is comparable with that in the mandible, but a marked difference was found between both jaws regarding tooth type. Absence of one or two permanent teeth is found in 83% of the subjects with dental agenesis. A practical application of the results of the meta-analysis is the estimation of dental treatment need. Copyright Blackwell Munksgaard, 2004