ABSTRACT: BACKGROUND AND OBJECTIVES: The number of patients treated with oral anticoagulation (OAC) is increasing and these patients are monitored by International Normalized Ratio (INR). Bleeding complications are common and we speculate if this is related to the limitation of INR only reflecting the initiation steps of the haemostatic process. The objective of the present review was to reassess the evidence for using INR as a tool to guide administration of prothrombin complex concentrates (PCC) to OAC patients. A Medline and Cochrane database search was conducted using the following keywords: prothrombin complex concentrate, reversal of oral anticoagulation and international normalized ratio (INR). Thirty-three articles were contracted and a total of ten studies were eligible after applying inclusion and exclusion criteria encompassing only 339 patients. No consensus regarding optimal target INR value to aim for when reversing OAC was found. In three of the studies it was reported that patients reaching their target INR continued to bleed, whereas three studies reviewed reported good haemostatic response also in patients that did not reach their target INR. The present review found limited evidence for the usefulness of INR as a tool to monitor and guide reversal of OAC induced coagulopathy in patients with PCC, which is expected given that it is a plasma-based assay only reflecting a limited part of the haemostatic process.