The decolouration of several azo dyes, commonly used in the leather industry, by crude laccase obtained from Trametes hirsuta cultivation was assessed. Among the six dyes studied four showed a decolouration percentage higher than 50% in 4 h, whereas the other two showed more resistance to degradation. These results show the ability of laccase towards different dye structures as well as its enormous potential for the decolouration of recalcitrant azo dyes. (C) 2007 Elsevier B.V. All rights reserved.