In this paper, we apply the homotopy perturbation method (HPM), modied homotopy perturbation method (MHPM), variational iteration method (VIM), Adomian decomposition method (ADM), and modied Adomian decomposition method (MADM) to solve nonlinear mixed Volterra-Fredholm integral equations and its system. We investigate the approximate solution of this equation and its system via proposed methods. The validity and eciency of these methods are demonstrated through various numerical examples that illustrate the eciency, accuracy, and simplicity of the proposed methods. Moreover, the convergence and uniqueness of the solution of the suggested methods are conrmed and compared with the exact solutions.