Objectives: Assess laboratory and in-clinic performance of the OneTouch Select (R) Plus test system against ISO 15197: 2013 standard for measurement of blood glucose. Methods: System performance assessed in laboratory against key patient, environmental and pharmacologic factors. User performance was assessed in clinic by system-naive lay-users. Healthcare professionals assessed system accuracy on diabetes subjects in clinic. Results: The system demonstrated high levels of performance, meeting ISO 15197: 2013 requirements in laboratory testing (precision, linearity, hematocrit, temperature, humidity and altitude). System performance was tested against 28 interferents, with an adverse interfering effect only being recorded for pralidoxime iodide. Clinic user performance results fulfilled ISO 15197: 2013 accuracy criteria. Subjects agreed that the color range indicator clearly showed if they were low, in-range or high and helped them better understand glucose results. Conclusion: The system evaluated is accurate and meets all ISO 15197: 2013 requirements as per the tests described. The color range indicator helped subjects understand glucose results and supports patients in following healthcare professional recommendations on glucose targets.