Branching between the nondissociative, POCl3-, and dissociative, POCl2-, products of the POCl3 electron attachment reaction has been examined as a function of buffer gas pressure and temperature. A strong positive pressure dependence is observed for the nondissociative channel, where at 303 K, the %POCl3- increases from 31% at 1 Torr to 94% at 675 Torr total pressure. Conversely, the dissociative channel displays a strong positive temperature dependence. The effect of pressure and temperature on the relative amounts of POCl3- and POCl2-observed is discussed in terms of the competition between the collisional stabilization and dissociation rates of the POCl3-* excited intermediate. The decomposition of POCl3-* is modeled with Rice-Ramsperger-Kassel decomposition kinetics weighted by the vibrational energy distribution of POCl3 neutrals. This model provides an excellent simulation of the experimental pressure and temperature dependencies of the electron attachment process.