  We discuss the relic abundance of the right-handed sneutrinos in the
supersymmetric F_D-term model of hybrid inflation. As well as providing a
natural solution to the mu- and gravitino overabundance problems, the model
offers the lightest right-handed sneutrino as a candidate for thermal dark
matter. The F_D-term model predicts a new quartic coupling of purely
right-handed sneutrinos to the Higgs doublets that thermalizes the sneutrinos
and makes them annihilate sufficiently fast to a level compatible with the
current cosmic microwave background data. We discuss this scenario and identify
favourable regions of the parameter space within mSUGRA.
