The production of activated carbon from agricultural by-products is a research field of increasing interest as it deals with the problem of the disposal of agro-residues, at the same time producing an added-value product that can be used in a number of environmental applications. The paper presents an overview of the latest developments in processes for the production of activated carbon from agricultural by-products, with emphasis on the methodology applied, the effect of critical process parameters such as retention time, temperature, chemical to material ratio, as well as the adsorbing capacity of the activated carbons produced in removing select compounds from synthetic and real wastewaters. Agricultural by-products can be a source for activated carbon production with high surface areas and high adsorption capacity. (c) 2008 Society of Chemical Industry.