Sometimes, a person's reputation is harmed by someone in another country, and when the victim files a lawsuit, an international claim arises that requires the determination of jurisdiction. Considering that defamation is an intentional tort, applying a jurisdictional rule that focuses on the defendant’s intent and its effects in a specific place seems beneficial. However, how can such a jurisdictional rule be applied effectively? Has this jurisdictional rule been recognized in Iranian and U.S. law? Using a descriptive-analytical method and library resources, this research examines the approaches of these legal systems and evaluates the application of a jurisdictional rule based on the defendant’s intent and its effects. The findings of this research indicate that U.S. law has established a jurisdictional rule whereby the court has jurisdiction over a defamation claim if the focal point of the harm to the victim's reputation and the defendant’s intentional harmful act is within its territory. However, Iranian law has not recognized such a rule. The analysis reveals that while applying this rule could promote fairness between the parties, its high degree of flexibility may lead to inconsistencies in judicial approaches when exercising jurisdiction.