CONTEXT Dental caries is one of the commonest oral diseases in children. Despite this fact, not many studies have been done on this issue among school children in Shimla. AIM To assess the prevalence of dental caries and treatment needs among schoolchildren aged 12 years and 15 years in Shimla city, Himachal Pradesh, India. With this study we also aimed to establish reliable baseline data. DESIGN Cross-sectional study. MATERIALS AND MATERIALS This study was conducted among 12 - and 15 - year old schoolchildren in Shimla city, Himachal Pradesh-India. A sample of 1011 schoolchildren was selected by a two-stage cluster sampling method. Clinical recording of dental caries, was done according to WHO diagnostic criteria (1997). STATISTICAL ANALYSIS The statistical tests used were the t- test, and the Chi-square test. RESULTS The prevalence of dental caries was 32.6% and 42.2% at 12 years and 15 years respectively. At 12 years of age, the mean Decayed Missing Filled Teeth was 0.62 ± 1.42 and it was 1.06 ± 2.93 at 15 years of age. Females had higher level of caries than males at both the ages. Dental caries was higher in children from government schools as compared to those from private schools. The 'decayed' component was the biggest contributor to the DMFT index. The highest treatment need at both ages was one surface restoration. CONCLUSION The caries experience of 12- and 15- year-old children was low compared to WHO - 'recommended' values. Effective oral health promotion strategies need to be implemented to further improve the dental health of school children in Shimla city.