BACKGROUND AND AIM: Our consortium of exposure scientists and health researchers –CHAIR-India is developing a nation-wide exposure model for particulate matter. Our aim is to build a comprehensive database which will help develop/validate a hybrid exposure model. In this process, we attempt to discuss the gaps and indicate potential solutions to improve air pollution monitoring data quality. METHODS: Data was collected from online monitors from Central Pollution Control Board (CPCB) Continuous Ambient Air Quality Monitoring Stations (CAAQMS) as well as offline monitors as part of the National Ambient Air Quality Monitoring Programme (NAMP) between the years of 2005-2020. Variables assessed were unique station name/ID, dates, pollutant variables – (PM2.5, PM10), geographical information (lat/long) and type of PM data generated (Gravimetric/BAMS). These data were collated, sorted and assessed for consistency and validity. RESULTS:While data from online stations (BAMS) have a high level of completeness in recent years (2015 onwards), older data is sporadic and mostly available for Delhi and Maharashtra. The NAMP station data far outnumbers the CAAQMS data in size and spread, particularly for the years before 2015, but presented greater challenges with completeness and accuracy, especially with the geographical metadata. CONCLUSIONS:The broad reach of CAAQMS and online stations in recent years make them an attractive option for air quality research post 2015 with important opportunities to expand the evidence base for India on health effects of air pollution. Comprehensive nationwide and smaller regional studies will need to rely on data from NAMP to supplement the gaps in data from the online stations. Building capacities of state /regional agencies to enhance the quality and accuracy of data will provide impetus to a growing body of air pollution researchers in India. The CHAIR consortium will complement these efforts by developing an online platform with accurate metadata for all stations and sources for public access. KEYWORDS: India, Air Pollution, Monitoring, Data Quality, Research