The survey of biological methods for treatment of coloured textile wastewater is presented in the paper. Advantages and disadvantages of aerobic, anaerobic and anaerobic-aerobic processes of textile wastewater biodegradation are discussed. Special attention is given to the problems of removal of synthetic dyes from wastewater in conventional biological treatment systems. Alternative methods of decolourisation of textile wastewater based on natural ability of microorganisms (bacteria, fungi, algae) present in the environment are discussed.