BACKGROUND AND AIM: Dental caries is a multifactorial disease that affects people of any age, sex, and race. Significant caries index (SiC index) has been defined by World Health Organization (WHO) to evaluate caries status in different societies. The aim of this study was to determine the SiC index in 15-year-old children in Kerman. METHODS: This descriptive cross-sectional study was carried out on 300 of 15-year-old children that had been selected by systematic clustering sampling in Kerman. Data were collected by questionnaire (parents’ educational level, parents’ occupation, birth rank, number of children in family, tooth brushing, fluoride use, and regular dental visits) and clinical examination. Teeth were examined by dental mirror, according to WHO criteria. Data were analyzed in SPSS by using ANOVA, t-test, and Kruskal-Wallis tests. RESULTS: Thirty-two and nine brushed their teeth twice daily, 49.8% had never used dental floss, 47.8% had regular dental visit, 80.66% did not use fluoride mouthwash, and 34.4% were caries free. The mean of decayed, missing, and filled teeth (DMFT) was 1.83 ± 1.26 and SiC index was 3.80. There was a significant correlation between the SiC index and parents’ job and birth rank of student. There was also significant correlation between regular dental visit and use of fluoride mouthwash and SiC index. CONCLUSION: The prevalence of dental caries in 15 years student in Kerman is still high. Using DMFT and SiC indices together may help to show oral health status better than DMFT index alone. Further studies are recommended.