This article offers a discussion of the probable effects of a Worldwide Patent System for developing countries. It draws upon insights from the ongoing processes in the World Intellectual Property Organization and elsewhere relevant for the global patent system and discusses these features from a developing country perspective. For scientifically advanced developing countries the effect in their most advanced and most global enterprises is potentially positive as they will benefit as much as other multinational companies. In areas of research and development where these most advanced developing countries do not possess a high level of technological capacity, a Worldwide Patent System is unlikely to create any benefits for them. For countries with the ability to copy and produce inventions made by others a Worldwide Patent System will have a negative effect as inventors will have little opportunity to utilise the system, whereas they will be bound by a larger number of exclusive rights narrowing down their space for innovation. For the least developed countries an additional problem arises: it might become even more difficult to import essential goods because patents will be in force in these countries even though there is no production of that product in the country.