In this paper, an iterative Newton-type method of three steps and fourth order is applied to solve the nonlinear equations that model the load flow in electric power systems. With the proposed method (N-1) non-linear equations are formulated and solved iteratively to calculate the Voltage in each node of an electrical system. The justification of the method and its theoretical preliminaries are presented in this paper. The proposed method is applied to IEEE test systems, and their results are compared obtaining a maximum error of 0.5%. From the results obtained, the proposed method is an alternative to solve load flows in electrical systems.