Dyes are one of the widespread and hazardous contaminants that enter water bodies with wastewater. Reagent precipitation, ion exchange, coagulation, flotation, and other methods are used to remove dyes from aqueous environment. At the same time, sorption treatment is one of the most effective. The authors proposed to use sycamore leaves biomass for the dye "Methylene blue" extraction from aqueous environment. To investigate the process of adsorption of methylene blue by the leaves biomass, the sorption capacity of the material has been es-tablished; it is shown that the adsorption process is best described by the Freundlich model with a correlation co-efficient R2 = 0.9537.