Biomass treatment is one of the oldest methods available for the treatment of dyehouse effluent. A study critically examined recent developments in the use of biomass for decolorization of dyehouse water and removal of acidic dyes. Biomass decolorizes textile wastewater by adsorption and ion exchange mechanisms. Decolorization and dye adsorption studies for chitin, chitosan, microbial biomass (fungal biomass, bacterial biomass), unmodified lignocellulose biomass (sugarcane bagasse, wood shavings, maize cob, peat moss, rice hull), and chemically modified cellulose and lignocellulose (PAE-cellulose, carbamoyl cellulose, quaternized cellulose, quaternized lignocellulose) are discussed and companred. Of the biomass alternatives studied, only crosslinked chitosan fibrs and quaternized cellulose and lignocellulose had adequate dye binding capacities and sufficently rapid equilibrium kinetics to be cost effective acid dye absorbers. Because only quaternized lignocellulos is insensitive to dyebath pH, it offers the best potential treatment for acidic dye containing effluent.