The purpose of the study was to investigate caries of primary teeth and some associated back ground factors in a group of 580 nursery school children. The age of the children ranged from 3 to 8 years; 83% of them were of African origin, the remainder being Asians and Arabs. The mean dmft score of Africans was 2.3 and that of the other ethnic group was 4.3; 37% of the children showed zero caries experience. Boys of Asian and Arab origin had significantly higher dmft scores than the others. The most common location of caries lesions was on the proximal surfaces. The mean dmft score in the group of children with high socioeconomic standard (SES) was slightly higher compared to the children with lower SES, but the difference was not significant. The experience of caries found in this study is higher than that reported in most African studies.