In 2001, Thailand achieved universal coverage in access to health care. This led to a more equitable health care system, and a significant impact on the reduction in household out-of-pocket payments for health care. Empirical evidence from health information systems shows that there is now more equitable health care use across economic strata, the pro-poor nature of health care subsidies, especially for district health services provided by the Ministry of Public Health (MOPH), and a further reduction in the incidence of catastrophic and poverty impacts of health care expenditure. This is in line with the results of opinion surveys of public health administrators nationwide. The country-initiated National Health Accounts (NHA) compiled since 1994, are the backbone of resource tracking according to health care functions. In addition to the time-series NHA, monitoring and evaluation of equity in health care financial contributions is possible because of the long-standing, nationally representative household surveys conducted by the National Statistical Office (NSO), namely the Socio-Economic Survey (SES) and Health and Welfare Survey (HWS). Based on trust and mutual recognition and interests, a genuine partnership to improve the policy utility and equity monitoring capability of these two national databases has been fostered between the main user (MOPH) and data producer (NSO). Other large-scale regular surveys, conducted by health research institutes and various departments in the MOPH, contain quantitative data on health service use, payments for health care services, illnesses and health conditions and general and specific health behaviour. Other major data sources include disease surveillance and registry systems, and information on health care use in administrative data and routine reports, which all suffer from a lack of data on the social determinants of health. The time-series NSO national datasets have ample parameters for monitoring health equity and are a real national asset in Thailand for evidence-based, equity-related policy formulation and evaluation.