Abstract: We estimate the determinants of utilisation of physician and hospital services in Belgium using four different regression techniques. We apply a one- and two-part panel count data model, and a one- and two part cross-section count data model. We conclude that the two-part panel count data model is most appropriate as it controls for unobserved heterogeneity and allows for a two-part decision making process. The estimates of the determinants of utilisation of health care are then used to calculate indices of horizontal inequity. We find that there is little difference between the indices based on cross-section and the indices based on panel estimators. We further present longitudinal evidence on equity in Belgian health care and find that all indices are stable across years. We also find that general practitioner and hospital care are pro-poor distributed, while horizontal equity applies to specialist care. We further show that the inequity might be different for (i) the probability to contact the health care sector, (ii) the conditional number of visits, and (iii) the unconditional number of visits.