The study is concerned with the three-dimensional analysis for non-isothermal forging of a steam turbine blade by the thermoviscoplastic finite element method. The analysis includes deformation of the workpiece and heat transfer of the workpiece and the die. In the transient heat-transfer analysis, the finite element method is adopted for the workpiece, while the boundary element method is adopted for the die. The non-isothermal analysis is compared with the isothermal analysis as well as with the experimental results. The length of the forged blade increases by 20 per cent as compared to the initial billet, as confirmed by the deformed configuration of both the computation and experiment.