Aim To assess socioeconomic‐related inequality in oral health‐care utilisation among older Thais. Method The data on 8951 and 11 402 older Thais (≥60 years) from national representative Thailand Health and Welfare Surveys (HWS) of 2003 and 2009, respectively, were analysed. Descriptive analyses were performed on oral health‐care utilisation, and a concentration index (CI) quantified the extent of socioeconomic‐related inequality in oral health‐care utilisation. Results Analyses indicated that socioeconomic‐related inequalities in oral health‐care utilisation among older Thais existed, and tended to favour those of higher socioeconomic status. However, the older poor were more likely to utilise oral health care at public facilities, particularly primary care facilities, than those of higher socioeconomic status. Conclusion Despite universal coverage policy, socioeconomic‐related inequalities in oral health‐care utilisations exist among the older Thais. To alleviate these, strengthening the primary health‐care system deserves particular attention.