Using all standard scattering mechanisms the hole mobility in a metal oxide semiconductor field effect transistor SiGe conduction channel at 17 K and room temperature was calculated. The mobility measurements were performed at different bath temperatures in the range of 4–300 K. The 4 K peak mobility at a sheet carrier concentration, nh, of 2.1 × 1011 cm− 2 is 5100 cm2 V−1 s− 1 while the 300 K mobility has a peak value of 350 cm2 V−1 s− 1. By comparing between theory and measurements it is shown that the interface impurities and surface roughness more strongly limit the mobility than alloy scattering does.