In this paper, we examine the impact of decentralization of health care administration on inequity in health care access in Canada. We extend previous studies in two ways. First, to explore the spatial dimension of inequity, we adopt a perfect decomposable inequality measure--the Theil index--in our analysis. Secondly, we conduct a before and after comparison of a change in the degree of decentralization in Canada--the introduction of the CHST in 1996/1997. This may shed some lights on the casual relationship between decentralization and health-related inequity. The results of our analysis show that the overall inequity in health care utilization is mostly explained by variations within provinces in Canada. The increase in the degree of decentralization is related to lower degree of overall and within-province inequity in the use of GP and hospital services, and lower between-province inequity in the use of all the three health care variables examined in this paper.