Decolorization of methyl orange with live and autoclaved biomass fungi were studied. Sixteen different fungi including Fusarium, Trichoderma, Humicola, Aspergillus, Penicillium, Paecilomyces, Alternaria and Beauveria were evaluated. The highest decolorization activity was observed with Fusarium acuminatum and Humicola fuscoatra. Decolorization efficiencies of live and autoclaved biomasses were compared. In addition, spores of eight fungi showing high decolorization efficiency were inoculated for decolorization ability. The most successful fungi were Penicillium sp. and Fusarium sp. For adsorption studies, methyl orange decolorization with live and autoclaved biomasses were found most suitable with malt extract compared to yeast extract peptone medium.