The majority of the organizations see technical controls as the solution to their problems around information security. Moreover, it was obviously proved with providing all of these technological techniques that errors of human are not avoidable Unintentional Insider Threats (UIT) are the biggest insider risk of all, which defined as an employee former/current, business partner or contractor who had/ has access authority to the network, system or data of an organization and who, without malicious intent, damages the organization's information or information systems through action or inaction. Thus the objective of this paper is to; determine the countermeasures of UITs have been reported in the literature. This paper achieves a structured literature review of a wide collection of existing literature on UITs countermeasures. The review of literature identified a group of significant countermeasures against UITs which Can be used for improve organizations’ security policy for reducing and minimizing reducing the risks connected to UITs.