This paper reports the measurements of the interfacial tension in a water methane system at temperatures from 278.15 K to 298.15 K and pressures up to 10 MPa. The measurements using the pendant drop method were performed at various pressures lower than or, at the highest, nearly equal to the hydrate/liquid/gas equilibrium pressure corresponding to each of the following prescribed temperatures: 278.15 K, 283.15 K, 288.15 K, 293.15 K and 298.15 K. The obtained data show that at each temperature the interfacial tension decreases almost linearly with the increasing pressure, indicating that the observed decrease in the interfacial tension results from the promotion of methane adsorption onto the interface with the increasing pressure. (C) 2015 Elsevier B.V. All rights reserved.