The aim of this study was to measure and compare methane oxidation rates of arable and grassland soils that received 7.5tha −1 y −1 of noncontaminated aerobically treated sewage sludge for ten years. Arable soils showed generally lower methane oxidation rates (from 6 to 15∗10 −3 h −1 ) than grassland soils (from 26 to 33∗10 3 h −1 ). Oxidation rate constants (k) of soils amended with sewage sludge were remarkably close to their respective untreated controls, but a soil, that had received a tenfold sewage sludge application (i.e. 75tha −1 y −1 ), showed a statistically significantly higher k-value. Laboratory addition of up to 1000mgPbg −1 soil to this soil did not cause any significant change in methane oxidation, but caused a decrease from 13.9 to 10.9×10 −3 h −1 in the control soil. Addition of Zn was much more toxic than Pb, with a significant decrease at 300μgg −1 soil rate and an almost complete inhibition at 1500μgg −1 soil rate. Higher resistance was evident of sewage sludge treated soil in comparison to control soil, for both biomass C and CH 4 oxidation activity.