A comparison was made of the linear least-squares method and a nonlinear least-square method of the Langmuir isotherm and pseudo second order kinetic model for the biosorption of methylene blue onto rice husk. The parameters obtained from the linear method and the nonlinear method were different. The error analysis was performed. Results showed that both linear and nonlinear method can be used to fit the experimental data. The nonlinear method may be a better way to obtain the desired parameters.