Load flow studies play a vital role in planning the future expansion of power system as well as for deciding the optimum operation of the existing power system. Three phase asymmetrical power flow studies are recommended for unbalanced power systems such as distribution networks. Unbalanced loading, single phase and two phase shunts make the system operation unbalanced leaving the application of conventional load flow techniques away from the scene. The paper presents an unbalanced power flow algorithm based on the current injection technique with full Newton-Raphson formulation. The proposed method is validated using IEEE four bus test network.