  Recent higher-order results for precision observables in the Standard Model
(SM) and the Minimal Supersymmetric Standard Model (MSSM) and for the neutral
CP-even Higgs-boson masses of the MSSM are summarized. Furthermore a brief
discussion of the technical aspects of evaluating higher-order corrections in
the electroweak theory is given. In the SM, results for the Higgs-mass
dependence of the precision observables are analyzed. The exact two-loop
results for the Higgs-mass dependence of the fermionic contributions are
compared with the results of an expansion in the top-quark mass up to
next-to-leading order. In the MSSM, results for the leading two-loop
contributions to the precision observables and to the masses of the neutral
CP-even Higgs bosons are discussed. The latter are compared with results
obtained by renormalization group calculations.
