Dissociative electron attachment to CCl 3Br has been studied using a flowing afterglow/Langmuir probe (FALP) and a crossed beam technique. In the FALP experiment the overall attachment rate coefficients and the branching ratio into the Cl − and the Br − product channels, R = Cl − ( Cl − + Br − ), were measured as a function of the gas temperature, T g, in the range of 300–540K and the electron temperatures, T e, from T g to 4000K indicating that R approached the statistical value of 0.75 at the highest T g. At T g = 540K both Cl 2 −1 and ClBr − molecular ions were observed at about the 2% level. An apparent activation energy of 55 meV for the overall attachment reaction was derived using a model developed previously to describe the dependence of dissociative electron attachment rates on T g and T e. The crossed beam experiment provided relative attachment cross-sections for the production of Cl − and Br − as a function of electron energy, E, from near zero up to ∼2 eV at several T g within the range 311–423 K. The absolute cross-sections at T g = 311K were obtained from the FALP value using a calibration procedure. At low E the overall attachment cross-section varies as E −1 in accordance with s-wave capture theory. In accordance with the FALP data R increases from 0.2 at low E and the lowest T g to the statistical value of 0.75 at high E and high T g. A peak observed in the cross-section at an E of about 0.7 eV is tentatively attributed to p-wave electron attachment. The rapid decrease of this peak cross-section with T g is ascribed to autodetachment.