Presumption of Validity of Patents and its Implication in Iranian legal system

The most important document to be used in any patent litigation is the patent itself which defines a patent right and determines its scope. The presumption of validity is a judicial presumption accepted in many countries.  But the applicability of this presumption relies on factors like the patent registration system and the way the registration authority works. This article examines the necessity of applying this presumption in Iranian legal system. The descriptive analytical method is applied in this article mainly and some case studies are done as well. Finally taking into account the two branches of Patents valid in Iran (patents issued under act of 1310 and those issued under the act of 1386) it concludes that this presumption should not be necessarily adopted in all Iranian courts according to the type of patents concerned because some are issued under a declaration system and others are issued under a substantive search system.