  The viability of the lightest neutralino as a dark matter candidate in the
Next-to-Minimal Supersymmetric Standard Model is analysed. We carry out a
thorough analysis of the parameter space, taking into account accelerator
constraints as well as bounds on low-energy observables, such as the muon
anomalous magnetic moment and rare $K$ and $B$ meson decays. The neutralino
relic density is also evaluated and consistency with present bounds imposed.
Finally, the neutralino direct detection cross section is calculated in the
allowed regions of the parameter space and compared to the sensitivities of
present and projected dark matter experiments. Regions of the parameter space
are found where experimental constraints are fulfilled, the lightest neutralino
has the correct relic abundance and its detection cross section is within the
reach of dark matter detectors. This is possible in the presence of very light
singlet-like Higgses and when the neutralino is either light enough so that
some annihilation channels are kinematically forbidden, or has a large singlino
component.
