Abstract: The viscosity of acetone-water liquid solutions has been measured over the entire concentration range at temperatures from 20°C. to generally within 1° to 10°C. of the normal boiling point. A capillary suspended-level viscometer was used, and the authors estimate that the results are accurate to ±0.2%. Both kinematic and absolute viscosities are give, and the results have been extrapolated to the boiling point of the solutions. The calibration of the Cannon-Ubbelohde viscometer is discussed in detail.