Reactions of the gaseous ion HCl + in its ground state were studied at 295 ± 5 K using a selected ion flow tube. Reaction rate coefficients and product ion branching ratios were determined for the reactants H 2, Xe, NO, O 2, CO, CO 2, N 2O, H 2S, COS, SO 2, NH 3 and CH 4. The reaction channels observed were proton or electron transfer, or both, except for H 2 where H-atom transfer was observed.