In this work, hole confinement in a MBE-grown Si/GeSi/Si quantum well on SIMOX substrate is investigated in detail using device simulation, electronic measurements, and optical techniques. The hole confinement is clearly demonstrated from GeSi PMOSFET measurements. The experimental results are in good agreement with device simulation results. The quantum confinement of holes in the GeSi quantum well on SIMOX is confirmed using photoluminescence measurements.