The residual fraction of mechanically–biologically treated municipal solid waste (MBT residual) was studied in the laboratory to evaluate its suitability and environmental compatibility as a support medium in methane (CH4) oxidative biocovers for the mitigation of greenhouse gas emissions from landfills. Two MBT residuals with 5 and 12 months total (aerobic) biological stabilisation times were used in the study. MBT residual appeared to be a favourable medium for CH4 oxidation as indicated by its area-based CH4 oxidation rates (12.2–82.3gCH4 m−2 d−1 at 2–25°C; determined in CH4-sparged columns). The CH4 oxidation potential (determined in batch assays) of the MBT residuals increased during the 124d column experiment, from <1.6 to a maximum of 104μgCH4 g dw - 1 h−1 (dw=dry weight) at 5°C and 578μgCH4 g dw - 1 h−1 at 23°C. Nitrous oxide (N2O) production in MBT residual (<15μgN2O kg dw - 1 d−1 in the CH4 oxidative columns) was at the lower end of the range of N2O emissions reported for landfills and non-landfill soils, and insignificant as a greenhouse gas source. Also, anaerobic gas production (25.6l kg dw - 1 during 217d) in batch assays was low, indicating biological stability of the MBT residual. The electrical conductivities (140–250mSm−1), as well as the concentrations of zinc (3.0mgl−1), copper (0.5mgl−1), arsenic (0.3 mgl−1), nickel (0.1 mgl−1) and lead (0.1 mgl−1) in MBT residual eluates from a leaching test (EN-12457-4) with a liquid/solid (L/S) ratio of 10:1, suggest a potential for leachate pollutant emissions which should be considered in plans to utilise MBT residual. In conclusion, the laboratory experiments suggest that MBT residual can be utilised as a support medium for CH4 oxidation, even at low temperatures, to mitigate greenhouse gas emissions from landfills.