  We review the currently most accurate evaluation of the W boson mass, M_W, in
the Minimal Supersymmetric Standard Model (MSSM). It consists of a full
one-loop calculation, including the complex phase dependence, all available
MSSM two-loop corrections as well as the full Standard Model result. We analyse
the impact of the phases in the scalar quark sector on M_W and compare the
prediction for M_W based on all known higher-order contributions with the
experimental results.
