Inelastic differential scattering cross sections for the system K/N 2 have been measured in the small-angle regime for E x in the range 80–600 eV deg. A cross beam time-of-flight technique was used to measure energy transfer effects occurring in the collision. The dominant inelastic process in the region explored was production ot the K(4 2P) state together with simultaneous vibrational excitation of the N 2 molecule. The observations are in excellent agreement with published potentials and a simple classical model involving an intermediate with considerable negative-ion character.