The recombination reaction NF2+F+M→NF3+M has been investigated theoretically using a RRKM approach. Adequate agreement is found with the available association and decomposition data in low pressures of He or Ar. The recombination in 4 atm of Ne is calculated to be much slower than would be expected from extrapolation of the low‐pressure, three‐body rate constant. In particular, little recombination should occur during a discharge or electron‐beam laser excitation pulse (≲1 &mgr;s), but reformation of NF3should be the dominant loss mechanism for F and NF2. The theoretical techniques used here should be equally applicable to other important recombination processes in laser media.