An analysis of the environments of leading manufacturing firms operating in the United States and in Australia produced a series of hypothesized differences in the strategies, organization structures, and market environments of firms in the two countries. Parallel hypotheses about differences between domestic Australian firms and subsidiaries of foreign multinationals operating in Australia were also developed. The hypotheses were by and large supported when tested on data obtained from leading corporations in the two countries. The United States sample, drawn from the Fortune "500," contained no foreign subsidiaries, whereas about half of the Australian sample, drawn from the 100 largest Australian manufacturers, were subsidiaries of foreign-based multinational firms. Overall, the U.S. firms face faster-growing and more competitive markets, are more international and invest more in R&D, particularly for new products. Domestic Australian firms are active acquirers and resemble United States firms in terms of product diversity, diverstiture activity and organization, but they are not international in focus and their limited investment in R&D is process-oriented. Australian subsidiaries of foreign multinationals are even less international than domestic firms, narrower in product scope and have simpler organizations.