As pharmaceutical industries have rapidly modernized and globalized, borders have been blurred and multiple entities in different countries are now involved with the manufacture, supply, distribution, dispensing and administration of even a single drug in the pharmaceutical industry. The cross jurisdictional nature of the modern pharmaceutical industry presents new challenges to limitations on the extraterritorial reach of US patents. The enforcement of US patents outside the jurisdictional boundaries of the USA has judicially evolved through cases such as Deep South, Microsoft, Bayer AG, Union Carbide, AT&T, Cardiac Pacemakers and others. This article explores the effects of recent cases on the extraterritorial enforcement of US pharmaceutical patents, particularly when different types of claims are involved.