The calculation of the cosmological relic density of the dark matter candidate within supersymmetric models is an interesting possibility to obtain additional constraints on the supersymmetric parameter space with respect to collider, electroweak precision, and low-energy data. Considering future cosmological precision measurements, radiative corrections can play an important role in the analysis. We present full QCD and SUSY-QCD corrections to neutralino pair annihilation into quark-antiquark pairs and analyze their impact on the neutralino annihilation cross section and the relic density. By comparing to the relic density obtained from a pure leading order calculation, we show that the corrections strongly influence the extraction of SUSY mass parameters from cosmological data.