The United States Court of Appeals (Federal Circuit) decision in Amgen Inc v Hoechst Marion Roussel Inc 314 F 3d 1313 (2003) poses significant concerns for promoting competition in the biotechnology sector. The decision is, in effect, a win for old technology and "Big Pharma" at the expense of new and substitute technology that might have been expected to introduce new entrants and competition into the sector. This article reviews the key outcomes of that decision and places the consequences into a competition discourse concluding that the Court of Appeals' preference for favouring a construction and written description that confounds new market entrants may not be desirable for competition.