The hot deformation behavior of waspaloy alloy has been investigated by two-pass hot cogging process. The paper presents theoretical end experimental analysis of deformations and microstructural  evolutions. The results of a thermo-mechanical simulation for the spatial hot cogging process on the shaped anvils with the application of the three–dimensional finite element method, are presented. The numerical calculation gave an assessment of the effective strain, effective stress, mean stress and temperature distributions in the work-piece. Models for predicting the evolution of microstructure in waspaloy alloy during thermomechanical processing were developed for dynamic recrystallization and grain growth phenomena. The Johnson–Mehl–Avrami–Kolmogorov theory was introduced to characterize the evolution of DRX volume fraction and grain size. The effects of processing parameters on the microstructure evolution of waspaloy alloy hot cogging process were discussed by integrating the thermo-mechanical coupled finite element method with the derived microstructure evolution models.  The influence of shape of the anvils on the grain size after dynamic recrystallization was analyzed. The numerical analysis was performed using a commercial program "DEFORM - 3D" with thermo-mechanic and microstructural evolution coupled. The results are compared with the experimental data, a good agreement between the predicted and experimental results was obtained.