Large socioeconomic inequalities still exist in oral health. It is already known that oral health-related behaviour may contribute to these inequalities, but why people with a lower socioeconomic position behave less healthily is not easily understood. A possible explanation that integrates insights on health behaviour, stress, and financial resources is the pathway of behavioural responses to financial strain. The aim of this study was to assess to what extent financial strain is associated with clinically assessed caries experience in a population-based study of dentate adults, independently of other socioeconomic indicators. Furthermore, the potential mediating pathways of oral health-related behaviours (oral hygiene, dietary habits, preventive dental visits) were explored. Dentate participants, aged 25-44 years, taking part in a survey on oral health and preventive behaviour in the Netherlands in 2013 were clinically examined on - among others - caries experience (DMFS index) and level of oral hygiene (OHI-s index). Financial strain, frequency of tooth brushing, dietary habits, attendance of (preventive) dental visits in the past year, and demographic variables were assessed via questionnaires. Negative binomial hurdle models were used to study the association between financial strain and DMFS and between oral health behavioural indicators and DMFS. Although it was observed that experiencing financial strain did not seem to affect whether there is any caries experience or not, among those having any caries (DMFS >0) suffering from financial strain was associated with a higher caries prevalence, independent of educational level and income. None of the studied potential mediators could explain this association.