The feasibility of the utilisation of freshwater methanogenic sediments as inocula for anaerobic wastewater treatment processes at low temperature (20°C) was studied. This process appeared to be stable for the three substrates studied: pig manure, distillery waste and sewage sludge, with a total solids concentration of 40, 25 and 32 kg.m−3, respectively. The range of organic load applied was 0.1 ‐1.3 kg COD.m−3d−1; biogas production ranged from 0.195 to 0.257 mB3.mD−3d−1, and the percentage of methane was of 66 ‐ 76%. The results reported permit to conclude that freshwater sediments are a promising alternative to conventional anaerobic sludge for the inoculation of lowtemperature anaerobic digesters. © 1990 Publications Division Selper Ltd.