Three populations in South- and North-Thingeyjarsýslas, Northeast Iceland, were surveyed for the presence of torus palatinus. A total of 987 schoolchildren (489 male and 487 female) were examined. A statistically significant difference was noted between the prevalence in South-Thingeyjarsýsla (33.3%) and North-Thingeyjarsýsla (14.6%). Prevalence and size were affected by age and population but not by sex. An association between torus palatinus and torus mandibularis was not found. Secular changes in the occurrence of torus palatinus in Icelanders emphasize the importance of environmental etiological factors and diminish the value of torus palatinus as a racial trait.