There has been limited field research in the literature on international marketing and international business in the examination of the relative successes by firms in implementing global marketing strategies through their overseas subsidiaries in competition with one another abroad. The focus of this paper on this neglected area has been the conduct of primary research with American and Japanese firms to examine the internationalization of their marketing strategies through their subsidiaries to enhance their competiveness in an overseas market, the UK. The research programme implemented in both the US and Japan with senior company personnel involved with the international marketing function was to examine their marketing perceptions and attitudes with reference to the UK market. The subsequent analyses sought to isolate their evaluations of the various components of their international marketing strategies and their supporting managerial structures.