Abstract The canteen and mess wastes (CMW) which are rich in organic constituents were employed in this study for biogas generation. Some of the environmental and operational parameters influencing biogas yield and its methane content were optimised in a 200 l Khadi and Village Industries Commission of India digester. A high gas yield of 0·981 m 3 kg −1 volatile solids (VS) added with a methane content of 50% was obtained, i.e., about 65% substrate utilisation. The hydraulic retention time (HRT) was successfully reduced to 20 days, while the loading rate reached as high as 100 kg total solids (TS) m −3 d −1. Thus the anaerobic digestion of CMW forms an effective ‘two-in-one systems’ involving waste utilisation and energy generation.