In this work we present an analytical model of the threshold voltage of SiGe p-channel metal oxide semiconductor field effect transistor based on the solution of the two-dimensional Poisson’s equation and the ground state wave function of Fang and Howard, and taking into account the space charge in the channel and its effect on the surface potential. It is seen that the experimental data are well fitted within the experimental error that shows the appropriateness of the implemented model. Also comparing the calculated results to that of the calculated from the available recent reported models indicates a reasonable improvement to them.