The kinetic energy release of desorbed F − ions formed via dissociative electron attachment (DA) to condensed CF 4 is measured by means of an electrostatic energy analyzer. The condensed phase results are compared to DA from gas phase CF 4 where F − appears with high kinetic energy from a feature at 6.2 eV (assigned as CF 4 − ( 2 T 2 ) shape resonance) and with low kinetic energy from a second feature located at 7.7 eV (assigned as a Feshbach type CF 4 ∗− resonance with T 1 symmetry). In contrast, the kinetic energy of desorbed F − continuously increases with electron energy over the entire range of the resonance feature (5–9 eV) with a slope of 0.25 for the most probable energy of F − . The present results indicate that the transfer of electronic energy into nuclear motion is considerably modified in the condensed phase.