In patients admitted to accident and emergency departments for anticoagulant use-related major hemorrhage and requiring urgent surgery or life-saving invasive intervention, the international normalized ration (INR) value should be rapidly corrected and bleeding should be controlled. With prothrombin complex concentrate (PCC), when used at optimal dose levels, target INR values are achieved within 15 min. In this study, we aimed to discuss the efficacy of the used four-factor PCC in 10 patients who were admitted to the accident and emergency department because of oral anticoagulant use-related major bleeding. Of all the patients to whom PCC treatment was administered, targeted INR levels could not be attained in 2 patients (20%). For our cases with gastrointestinal bleeding, the average baseline INR value was 7.3, while the average INR value after PCC administration was 1.9. For our subdural hematoma cases, the median baseline INR value was 2.5, while the median INR value after PCC administration was 1.3. We believe that PCCs used in eligible patient groups, as in this case series, may provide the desired results at lower doses and that they may be safer with regard to complications.