This paper tests for income-related reporting heterogeneity in self-assessed health (SAH). It also constructs a synthetic measure of clinical health to decompose the effect of income on SAH into an effect on clinical health (which is called a health production effect) and a reporting heterogeneity effect. We find health production effects essentially for low-income individuals, and reporting heterogeneity for the choice between the medium labels, i.e. 'fair' vs 'good' and for high-income individuals. As such, SAH should be used cautiously for the assessment of income-related health inequalities in France. It is however possible to minimize the reporting heterogeneity bias by converting SAH into a binary variable for poor health vs other health statuses.