  We determine the neutralino and chargino masses in the MSSM at one-loop. We
perform a Feynman diagram calculation in the on-shell renormalization scheme,
including quark/squark and lepton/slepton loops. We find generically the
corrections are of order 6%. For a 20 GeV neutralino the corrections can be
larger than 20%. The corrections change the region of $\mu,\ M_2,\ \tan\beta$
parameter space which is ruled out by LEP data. We demonstrate that, e.g., for
a given $\mu$ and $\tan\beta$ the lower limit on the parameter $M_2$ can shift
by 20 GeV.
