Adsorption of manganese(II) ion on aluminium oxide and iron(III) oxide at various temperatures was studied. The amount of adsorbed and excess ions in the solution at equilibrium were determined by neutron activation analysis(NAA) using Cf-252 as the neutron source. The influences of electrolytes on the isoterms of adsorption were also investigated. Adsorption isotherms of manganese(II) ion on aluminium oxide were found to follow the Langmuir adsorption isotherm with the ions being more adsorbed at higher temperature. Adsorption on ion(III) oxide, however was found to follow the adsorption isotherm with less of adsorption than on aluminium oxide. Some electrolytes such as calcium chloride and aluminium chloride had some effect on the adsorption.