The prevalence of developmental defects of enamel was assessed in 4805 16-year-old schoolchildren in fluoridated and non-fluoridated areas in Malaysia. In this sample, the mouth prevalence was 56.0%; tooth prevalence was 21.8%. There were significant differences between children in fluoridated and non-fluoridated areas, urban and rural areas as well as between the ethnic groups. However, there was no significant gender difference. Prevalences were lower than those reported in most other Asiancountries. However, direct comparisons could not be madedue to differences in indices and methodology used.