The effect of pretreatment on the Cd2+ biosorption capacity of mycelial biomass of Pleurotus florida was investigated. For this purpose, the biomass was subjected to physical treatments such as heat, autoclaving and freeze drying and chemical treatments using acids, alkali and organic solvents. All the pretreatment methods improved the biosorption of Cd2+ in comparison with live biomass of P. florida. Among physical treatments, freeze drying showed significant improvement in Cd2+ sorption capacity. Pretreatment of biomass with NaOH showed maximum cadmium biosorption followed by formaldehyde and methanol treatment. © 2007 Academic Journals.