The ion/molecule reactions of HNO3 with Cl- n and In - (n = 2,3) have been studied at room temperature by means of a flow tube coupled to a quadrupole mass spectrometer. The reaction rates for Cl- n + HNO3 for n = 2 and 3 have been determined relative to the known reaction rate for n = 1. Nitric acid reacts with Cl- 3, resulting mainly in the product ion NO- 3 · HCl. The product ion(s) of the slower two body reactions of Cl- 2 could not be determined unambiguously, but from thermodynamical considerations NO- 3 · HCl seems to be the most probable candidate. For the study of I- n + HNO3, the known reaction CO- 3 + HNO3 was used as a reference. No reaction has been observed for HNO3 with I- n ions (n = 2,3). Additionally, rate constants have been determined for the reactions of nitric acid with CO- 4, (NO3OH)-, (NO3HO2)- and NO- 3 · HCl.