AbstractBiogas production from cowdung is well studied. Coconut pith is an agricultural waste available in large quantities in Kerala: the possibility of using coconut pith for biogas production was studied. It was found that coconut pith in combination with cowdung gives considerable amount of biogas, while alone it did not produce any gas. The optimum combination was found to be 60% pith and 40% cowdung. Study of dilution effect on the slurry showed that the optimum solid‐liquid ratio is 1:20. Partial removal of lignin from pith increased the rate of biogas production. Gas produced from a mixture of cowdung and pith was found to have a higher methane content than that produced from cowdung onl