The present study introduces the concept of a newly designed scanning viscometer with a capillary tube for use in measuring whole blood viscosity without the use of anticoagulants in a clinical setting. Both flow rate and pressure drop measurements that are usually required for the operation of a capillary tube viscometer are replaced with a single measurement of liquid-height variation with time. In addition, the present method overcomes the drawbacks of conventional viscometers in the measurement of the whole blood viscosity. First, with the present study, whole blood viscosity can be accurately and consistently measured at 37 degrees C over a wide shear rate range including shear rates as low as 1 s(-1). Second, the present method can measure whole blood viscosity over a range of shear rates in less than 2 min without any anticoagulants so that one can measure the viscosity for unadulterated blood.