Dental caries was recorded using WHO index (1983) and Moller's index (1966) in 1265 children in the age group of 5, 8, 11 and 15 years to determine the conversion and correlation figures, so as to facilitate cross comparison and quick appraisal where either of the systems have been used in epidemiological studies. The results revealed that dental caries was recorded higher with Moller's index as compared to the WHO index; on an average the difference was fourteen percent in point prevalence, one deft + DMFT and one and a half defs + DMFS.