In Thailand, laws relating to the enforcement of patent rights mainly involve the Patent Act of 1979, as a substantive law, and the Act for the Establishment of and Procedure for the Intellectual Property and International Trade Court of 1996, as a procedural law. Those Acts contain provisions relating to patent enforcement, particularly the rules of obtaining evidence from the opposing party. These provisions of law make civil suits on patent infringement worth pursuing. This article explores the burden and standard of proof aspect to determine the requirements that a patent holder must fulfill when a preliminary injunction and seizure order is sought from the Intellectual Property and International Trade Court.