Dental caries is the most common oral disease in human. Many epidemiological studies have been carried out worldwide to assess the prevalence of dental caries. In India also, several studies have been carried to fi nd out the prevalence of dental caries. To know the cause of disparity of prevalence of dental caries epidemiological study of all the regions is very important. The objective of this study was to determine the caries prevalence of school going boys and girls in and around Guwahati city, Assam, India. About 7233 school going boys and girls from 25 schools, aged 3-17 years participated in the study. Data were also recorded for frequency of taking sweets along with the prevalence of caries to see the association of caries with sweet taking frequency among different age groups. Data were collected using basic oral health survey (WHO) modified form. Results showed that 43.40% boys and girls were affected by caries. Boys (45.85%) showed higher prevalence than girls (40.92%) with a mean value of 5.60 ± 0.03 and 5.28 ± 0.03 respectively, and the difference was statistically significant. Caries is very negligible (1.82% in males and 1.75% in females) among those who occasionally take sweets or never take. Contrary to that, more than 94% sweet takers of both the sexes, those who take sweets more than 5 times a day are affected
by caries.