Introduction/Background Knowledge: Dental caries is one of the most important dental health problems in developing countries prevalence rate being 50 to 60 %. This study aimed to estimate the prevalence and severity of dental caries in subjects (both males and females, divided into 5 groups, age between 5 to 74 years) of the outpatient department of Rajiv Gandhi Medical College Kalwa, Thane. Methodology: This research was performed as descriptive and cross–sectional study for a period of 3 months from October to December 2018 on 1505 subjects. A revised World Health Organization (WHO) Questionnaire was used. The dental examination was performed according to the methodology of oral status evaluation recommendations by WHO. The prevalence of dental caries, DMFT/deft Index score, and Significant Caries Index were determined. The statistical test Chi–square test was used to find the association between variables. Results: The overall prevalence of dental caries was 99.26%. Mean DMFT Index was 4.08 and Caries Significant index was 6.97. No significant association was found between tobacco/ gutka consumption habit and dental caries. A high prevalence of caries was noted due to lack of proper oral hygiene awareness and lack of accessible and affordable oral health services