Growth of InAs/(Al, Ga)Sb quantum-well structures was performed on germanium substrates by molecular beam epitaxy. The structural and electrical quality was characterized by x-ray diffractometry, transmission electron microscopy, and Hall transport measurements. An optimization of the GaAs buffer layer growth enabled the deposition of InAs/Al0.2Ga0.8Sb quantum wells with electron mobilities of 27 500 cm(2)/V s at 300 K and 260 000 cm(2)/V s at 4.2 K. These values are comparable to those measured for identical structures grown on GaAs substrate. Our results demonstrate the feasibility of using germanium as an alternative cheap substrate instead of commonly used GaAs for the growth of InAs/Al0.2Ga0.8Sb quantum-well magnetic sensor devices. (C) 1999 American Institute of Physics. [S0003-6951(99)03922-4].