Some phenomena found in the polarographic reduction of indium(III) in acidic halide and thiocyanate media have been studied by a-c polarography. Speculation on the role of complex formation and anion-induced adsorption on the polarographic reduction at potentials near the half-wave potential are given. At low ligand concentrations the a-c peak potential is believed to be influenced by anion-induced adsorption while at high ligand concentrations the value is the thermodynamic value predicted from bulk complexation equilibria. The unusual d-c minimum found at more negative potentials and the above phenomena are discussed in terms of the coupled occurrence of electroinactive left bracket In(H//2O)//x right bracket **3** plus ions at potentials where the complexed ion is electroactive and anion-induced adsorption. The reduction mechanism at the half-wave potential and at more negative potentials are concluded to be similar.