This study assessed trends in equity of access to reproductive health services and service utilization in terms of coverage of family planning, antenatal care and skilled birth attendance in Thailand. Two health indicators were measured: the prevalence of low birthweight and exclusive breastfeeding. Equity was measured against the combined urban-rural areas and geographic regions, women's education level and quintiles of household assets index. The study used data from two nationally representative household surveys, the 2006 and 2009 Reproductive Health Surveys. Very high coverage of family planning (79.6%), universal antenatal care (98.9%) and skilled birth attendance (99.7%), with very small socioeconomic and geographic disparities, were observed. The public sector played a dominant role in maternity care (90.9% of all deliveries in 2009). The private sector also had a role among the higher educated, wealthier women living in urban areas. Public sector facilities, followed by drug stores, were a major supplier of contraception, which had a high use rate. High coverage and low inequity were the result of extensive investment in the health system by successive governments, in particular primary health care at district and sub-district levels, reaching universality by 2002. While maintaining these achievements, methodological improvements in measuring low birthweight and exclusive breastfeeding for future reproductive health surveys are recommended.