Spoliation refers to the destruction or material alteration of evidence, or a party’s failure to preserve evidence related to a reasonably foreseeable litigation. Recent high-profile patent cases have been affected by alleged spoliation, including Hynix v. Rambus, Micron v. Rambus, and Samsung v. Apple. Spoliation sanctions can be severe enough to change a litigation’s outcome. Therefore, it is crucial that businesses engaged in patenting and licensing technologies understand spoliation law and take steps to preserve documents that may relate to patent litigation. This article reviews the standards for foreseeability relating to patent litigation, how different circuits determine whether to impose spoliation sanctions, and recent examples of spoliation sanctions in patent litigation.