Zymogram patterns of extracellular laccases of ten strains of Pleurotus grown on agar without addition of inducers, using 2.6-dimethoxyphenol, ρ-anisidine and o-tolidine as substrates, were obtained. Zymogram patterns were only similar for strains within same species, independently of the substrate used, six strains of P. ostreatus and one strain of P. ostreatus var. florida showed three isoenzymes, two strains of P. pulmonarius showed two isoenzymes and one strain of P. cornucopiae also showed two isoenzymes but in a different position in comparison to the other strains. These results showed that Pleurotus species produce a basal level of laccase activity and the number of extracellular laccase isoenzymes is species dependent.