White rot fungi are one of the key group of microorganisms that help to enrich the soil via degradation of wood. In the current communication, influence of iron and copper nanoparticles on the production of lignocellulolytic enzymes by Trametes versicolor have been investigated. The production of enzymes in the presence of the two nanoparticles was compared to that of ferrous and cupric ions respectively. Results show that both the tested nanoparticles alter the production profile of the lignocellulolytic enzymes when compared to the control set. The production of laccase was not influenced by iron nanoparticles but was effected by copper nanoparticles within 24 h of incubation. Both the nanoparticles decreased the production of beta-glucosidase, beta-xylosidase and cellobiohydrolase significantly. However, the production profile of Mn-peroxidase and remained statistically similar to that of control when the organism was incubated with iron and copper nanoparticles. The production profiles were also different when one compares the ionic form of metals and the nanoparticles, suggesting different mechanism of action of the particles on the organism. The difference in the production profile was not growth related as no significant difference was recorded for either form of iron and copper on the growth oft versicolor. (C) 2010 Elsevier B.V. All rights reserved.