Purpose: To perform the flapwise bending vibration analysis of a rotating cantilever Timoshenko beam.Design/methodology/approach: Kinetic and potential energy expressions are derived step by step. Hamiltonian approach is used to obtain the governing equations of motion. Differential transform method (DTM) is applied to solve these equations.Findings: It is observed that the ρIΩ²θ term which is ignored by many researchers and which becomes more important as the rotational speed parameter increases must be included in the formulation.Originality/value: Kinetic and potential energy expressions for rotating Timoshenko beams are derived clearly step by step. It is the first time, for the best of author's knowledge, that DTM has been applied to the blade type rotating Timoshenko beams.