The ion mobility and drift velocity of carbon tetrachloride have been measured at various ratios of E/Po, ranging from 1.0 to 9 volts/ (cm-Torr). The technique employed for these measurements utilizes a polonium alpha particle source which serves both as the source for ionization as well as the means for producing a reference pulse from a solid state silicon barrier detector. The thermal electrons which are produced are readily captured by carbon tetrachloride and the resulting negative ion, assumed to be CC14−, is detected by means of a proportional counter located at the end of the drift path. The zero field reduced mobility obtained for CC14−was 0.42 cm2/(volt-sec). The nature of the ionic species is explained in terms of the quantum mechanical theory of ionic mobility as put forth by Dalgarno.