  We perform a comprehensive analysis of the decays of charginos and
neutralinos in the Minimal Supersymmetric Standard Model where the neutralino
$\chi_1^0$ is assumed to be the lightest supersymmetric particle. We focus, in
particular, on the three-body decays of the next-to-lightest neutralino and the
lightest chargino into the lightest neutralino and fermion-antifermion pairs
and include vector boson, Higgs boson and sfermion exchange diagrams, where in
the latter contribution the full mixing in the third generation is included.
The radiative corrections to the heavy fermion and SUSY particle masses will be
also taken into account. We present complete analytical formulae for the Dalitz
densities and the integrated partial decay widths in the massless fermion case,
as well as the expressions of the differential decay widths including the
masses of the final fermions and the polarization of the decaying charginos and
neutralinos. We then discuss these decay modes, in particular in scenarios
where the parameter $\tan \beta$ is large and in models without universal
gaugino masses at the Grand Unification scale where some new decay channels,
such as decays into gluinos and $q\bar{q}$ pairs, open up.
