Experimental evidence is presented for radiative recombination of conduction electrons with hydrogenic impurity states in $n\ensuremath{-}\mathrm{I}\mathrm{n}\mathrm{S}\mathrm{b}$ between 2 and 4.2 K and magnetic fields up to 8 kG. The measured emission spectra agree with calculations by Larsen. In addition, radiative transitions between Landau levels are observed.