  We compute the Schroedinger functional (SF) for the case of lattice QCD with
Wilson fermions (with and without SW improvement) at two-loop order in lattice
perturbation theory. This allows us to extract the three-loop beta-function in
the SF-scheme. These results are required to compute the running coupling, the
Lambda-parameter and quark masses by finite size techniques with negligible
systematic errors. In addition our results enable the implementation of
two-loop O(a) improvement in SF-simulations.
