This study introduces the concept of a differential transform to solve the free vibration problems of a rotating twisted Timoshenko beam under axial loading. First, the concept of differential transform is briefly introduced. Second, taking a differential transform of a Timoshenko beam vibration problem, a set of difference equations is derived. Performing some simple algebraic operations on these equations, we can determine the jth natural-frequency, the closed form series solution of the jth mode shape. Finally, three cases-twist, axial force and rotation-are investigated to illustrate the accuracy and efficiency of the present method.