Background: Cancer registries are valuable resources for cancer control and research. To justify their purpose, their data should be of satisfactory quality by being comparable internationally, complete in their coverage, valid in their values and timely in reporting. This study aimed to assess the quality of the Ratnagiri Population Based Cancer Registry’s data for the years 2017–18 across the four dimensions of data quality.

Methods: Regarding comparability, the registry procedure was reviewed vis-à-vis the rules they follow for cancer registry operation. We have used four methods for validity: re-abstraction and re-coding, diagnostic criteria methods- like the percentage of microscopically verified (MV%) and of death certificate only (DCO%) cases, missing information like proportion of cases of primary site unknown (PSU%) and internal validity. Semi-quantitative methods were employed for assessing completeness. Timeliness for all years of registry functioning was assessed qualitatively.

Results: The overall accuracy rate of the registry was found to be 91.1% (94.7% for demographic and 88% for tumour details). Mortality to incidence ratios were found to be 0.50 for females and 0.59 for males. MV% was found to be 90.8% for males and 91.5% for females. The average number of sources per case was found to be 1.5. DCO% was found to be 2.7%. PSU% was 7.4%.

Conclusion: We have positive results regarding the data’s validity and comparability, but there is scope for improvement concerning completeness. Continuous training of the registry personnel and monitoring of the registry is recommended.