Introduction: Recognizing tooth health condition in each region is essential in order to take prevention measures. Dental exam is the most effective way of determining tooth health condition. The aim of this study was to determine decayed, missing and filled teeth (DMFT( indices and their related factors in 7-12 year old students in the city of Bandar Abbas in 2014.

Methods: In this descriptive - analytical cross sectional study a total of 768 school children (384 girls and 384 boys) were randomly selected from schools. Pupils were examined clinically for dental caries according to world health organization criteria (DMFT) and dental caries prevalence. Dental examinations of students were done under artificial light, using explorer, glove, mask, flash light and dental mirrors and results were recorded in world health organization standard form. Data was analyzed by SPSS 20 Software and Chi- Square tests. The differentiations with P<0/05 were significant.

Results: Dental caries prevalence "overall" was 65.2, in permanent dentition. The mean DMFT index was 1.61 in girls and 1.98 in boys. The mean DMFT index (total) was 1.8. Comparing means of DMFT index showed significant differences between the gender (P=0.009) and age (P=0.001).

Conclusion: Dental caries prevalence among 7-12 years-old school children in Bandar Abbas is higher than the global standard of WHO. The current study has identified a very high prevalence of caries among school children with male gender status. Therefore, improving the existing dental services and performing early oral education, prevention and treatment programs for school children seems to be necessary in the future.