We have investigated hot carrier dynamics in GaSb structures, bulk and quantum wells, using picosecond time-resolved photoluminescence. Bulk samples show remarkably little carrier heating which we attribute to rapid electron relaxation within the L valleys. Quantum wells show slower cooling than the bulk, which is consistent with similar measurements of other III-V systems. Strong Auger recombination heating of the plasma is found to be responsible for maintaining relatively high temperatures at times ≥ 25 ps. © 1989.