In this paper, He's energy balance method is applied to nonlinear vibrations and oscillations. The method is applied to four nonlinear differential equations. It has indicated that by utilizing He's energy balance method (HEBM), just one iteration leads us to high accuracy of solutions. It has illustrated that the energy balance methodology is very effective and convenient and does not require linearization or small perturbation. Contrary to the conventional methods, in energy balance method, only one iteration leads to high accuracy of the solutions. The results reveal that the energy balance method is very effective and simple. It is predicted that the energy balance method can be found wide application in engineering problems, as indicated in following examples. (C) 2009 Elsevier B.V. All rights reserved.