This chapter will explore some of the reasons for the lack of interaction between these two disciplines. We will first outline the history of CL to provide some background to the subsequent discussion as to why CL has not made much use of SFL. We will then discuss why SFL has not made much use of CL. In the final section, we will discuss ways in which SFL and CL are currently beginning to profit from each other, and ways in which the tools and methodology of corpus linguistics still need to be developed in order to fully support the needs of a sociological oriented theory such as SFL.