The classical theory of ion‐ion recombination in gases of high density is extended to allow for arbitrary ratios of the masses of the three species involved. Calculations are performed for the recombination of Ar+, Ar+2, Kr+, and Kr+2ions with F−and of Hg+and Ar+with Cl−in an argon gas. The effective two‐body rates peak between 2×10−6and 3×10−6cm3 sec−1at pressures above 1 atm.