Treatment of solid wastes using earthworms has been intensively investigated in recent years. Most of the agricultural, urban or industrial organic materials can be used for vermicomposting, ensuring that they do not contain toxic materials, which can harm the earthworms. The transformation of solid wastes into vermicompost is of double interest: a waste is converted into value-added product and it controls a pollutant that is a consequence of increasing population, urbanisation and intensive agriculture. This paper deals with the state of research on various aspects of vermicomposting process.