It has been generally agreed that Australia is a price follower on the world wheat market. However, to date, this has not been tested empirically. In this paper a transfer function model between prices of U.S.A. wheat and Australian wheat is set up to examine the existence, if any, of a leader-follower relationship. By employing the causality criteria as described by Granger, this analysis is implemented to draw inferences about causality among these wheat prices. Results indicated that a significant leader-follower relationship exists, with the U.S.A. taking the leader role. The results reported are particularly useful for wheat price forecasting work and provide a basis for further modelling work.