Fully microscopic models are used to study the temperature dependence of carrier losses due to radiative and Auger recombination processes in semiconductor quantum wells. The temperature (T) dependence of these loss processes is shown to depend on the carrier density, on details of the bandstructure, and on the Coulomb effects. While classical estimates based on simplified models predict a density independent 1/T-variation of the radiative losses, we find for the example of typical 1.3 mum InGaAsP structures a dependence closer to 1/T 3 at low densities. At high densities the temperature dependence is much weaker and can no longer be described by a simple power law. For a given density the Auger losses can be described by an exponential temperature dependence for limited temperature ranges if one uses a density dependent activation energy that can take positive or negative values.