Abstract—The increase in soil contamination by cesium (Cs) resulting from nuclear accidents has led to a resurgence of interest in microbe-radioactive interaction. The fate of Cs in the environment is mostly influenced by sorption processes. The aims of this study were as follow: 1) to apply a kinetic model of nonlinear regression and 2) to quantify the ability of soil fungi to adsorb Cs and determine the sorption isotherm. The results show that the r2 values for the pseudofirst- order kinetic model are higher than those for the pseudo-second-order kinetic model for all fungi genera (Fusarium sp., Trichoderma sp., and Aspergillus sp.). Then, the sorption equilibrium data were fitted to describe the sorption characteristics and quantify the sorption capacity with Langmuir and Freundlich isotherm. The results contribute to a better understanding of biosorption phenomena, under single-element conditions; the monolayer sorption capacities for Cs ions were 64, 38, and 30 g/g cell for Fusarium sp., Trichoderma sp., and Aspergillus sp., respectively which was best described by the Langmuir isotherm, indicating a monolayer arrangement of Cs on the external cell surface.