The structure of agriculture in Australia is experiencing extremely rapid change. Both firms that supply inputs to farmers and firms that process or market farm products are consolidating to create larger organisations. Mergers and acquisitions have enabled some firms to acquire relatively large market shares, thereby dominating portions of the food and fibre sector. The purpose of this article is twofold: first, it will provide a relatively current description of the concentration within selected subsectors of agribusiness in Australia. Second, it will explore portions of the available literature to determine the impact of consolidations upon profits, operating efficiency, and risk within agribusiness and agriculture. Because concentration is a very broad topic, many aspects, by necessity, are beyond the scope of this paper.