  If the energy density of the Universe before nucleosynthesis is dominated by
a scalar field phi that decays and reheats the plasma to a temperature T_{RH}
smaller than the standard neutralino freeze out temperature, the neutralino
relic density differs from its standard value. In this case, the relic density
depends on two additional parameters: T_{RH}, and the number of neutralinos
produced per phi decay per unit mass of the phi field. In this paper, we
numerically study the neutralino relic density as a function of these reheating
parameters within minimal supersymmetric standard models and show that the dark
matter constraint can almost always be satisfied.
