Measurements of the viscosity of superheated carbon tetrachloride were made at various superheats ranging from 0°C superheat to 37°C superheat. The measurements were made in three groups: two isotherms at 82.4°C and 88.3°C, and one isobar at 690 mm Hg. The three major drawbacks to attaining superheated conditions are vibrations (mechanical shock), impurities, and the maintenance of large volumes of superheated liquid. While the viscometer itself was a simple capillary viscometer, the special procedures and techniques required to attain the necessary superheats entailed the use of high vacuum equipment, liquid degassing systems, a vibration free table, and controlling systems to maintain the temperatures and pressures within the desired fluctuation limits. The results obtained show that the viscosity curve for carbon tetrachloride in the superheated regime appears to be a smooth continuation of the curve below the normal boiling point. A curve fit to the experimental data gave the following equation: This equation is valid over a temperature range of 70°C to 120°C. The standard deviation between the experimental data and values calculated from the given equation is ± 0.004, which is about 1%. The standard deviation between the fitted curve and previously reported data., which were obtained in a pressurized system, was ± 0.011, which is about 2.75%.