Multiple quantum well InAs/GaSb laser heterostructures with type III (type II broken gap) band alignment in the active region have been grown by molecular beam epitaxy. Intense electroluminescence was observed at room temperature (RT) with peak emission wavelengths in the range 1.95–3.4 &mgr;m. RT lasing has been achieved at 1.98 and 2.32 &mgr;m for the structures with 6 and 12 Å thick InAs quantum wells, respectively. ©1997 American Institute of Physics.