The effects of thickness asymmetry (Delta t) on the dynamic magnetization switching of exchange-coupled trilayers are investigated in this study. Elliptical thin films that have lateral dimensions of 200x100 nm(2) are considered. A significant difference in the dynamic switching behavior is observed depending on Delta t. Both the switching field and the switching time decrease as Delta t increases. A Fourier analysis of the magnetization oscillation, which is followed by the initial coherent rotation, shows multiple oscillation frequencies. This tendency is more pronounced at a larger Delta t. The main oscillation frequency tends to increase with an increase in Delta t. (C) 2008 American Institute of Physics. [DOI: 10.1063/1.3001805]