A survey was conducted among 5-6 and 12-13 years old school children of Puttur municipality, Karnataka State, India, to assess the prevalence of dental caries, malocclusion and dental calculus. A sample size of 200 subjects was taken for each age group and cluster-sampling method was used to select those schools which were to be included in the sample frame. Data collection was done using the Basic Oral Health Survey (WHO) form. The deciduous dentition alone was considered for 5-6 year old subjects while the permanent dentition alone was considered for those aged 12-13 years. A total of 427 subjects from 7 schools were studied. Results indicated that 81.25% of 5-6 year old subjects had dental caries (mean dmft = 4.86 +/- 4.16 S.D.) as compared to 59.6% of 12-13 year old (mean DMFT = 1.87 +/- 2.01 S.D.). The prevalence of malocclusion was 1.79% and 36.95% among those aged 5-6 year and 12-13 year, respectively. None of the 5-6 years old subjects had calculus on their teeth while 47.78% of 12-13 year old subjects exhibited the presence of dental calculus. Overall the prevalence of dental caries was found to be significantly higher among 5-6 year old subjects compared to 12-13 year old subjects. The prevalence of malocclusion and dental calculus was significantly higher among 12-13 year old subjects compared to 5-6 year old subjects.