The author of this paper was concerned in predicting the retail structure of accessories in the motor trade. In this research the fundamental importance of innovations was recognised and a discussion of the relevant theory is given in the first part of the paper. In the context of adoption of motor accessory shops by garages a theory of innovations in retailing is developed together with an example of its application in practice. It is further suggested that the content of this paper may assist in the development and refinement of institutional change in retailing and possibly in commerce as a whole.