Monitoring coagulation values in hemodialysis (HD) is integral to the care of patients with central venous catheters (CVCs) to maintain catheter patency. HD patients can have problems providing blood samples and may experience discomfort with venipuncture, but no consensus in the literature is available to identify a reliable and efficient method of obtaining an international normalization ratio (INR) value from a heparinized CVC line. This was a comparative study of three different methods of blood sampling for INR values. The INR samples were obtained from a peripheral venipuncture site, the CVC line, and the arterial bloodline sample port. The peripheral INR sample was used as the gold standard. The study occurred in a 60-station hemodialysis center in a 428-bed, urban, acute care hospital. The sample included 33 HD patients with patent dialysis CVC lines. Blood samples were drawn with a standardized protocol during one HD session from each of the three sites. The Pearson correlation coefficient for the peripheral sample versus the CVC line sample was 0.97 (p < 0.001) and was 0.99 (p < 0.001) between the peripheral sample and the arterial bloodline sample. Results revealed that both alternative methods are suitable for taking INR samples. As a result of this study, the arterial bloodline sample port method for INR sampling was introduced into the HD unit at this hospital. This method has proven to be simple, quick, accurate, and noninvasive to renal patients.