  In a series of publications [\ref{LNWW},\ref{Schroedinger}], L\"uscher et al.
have demonstrated the usefulness of the Schr\"odinger functional in pure SU(2)
and SU(3) gauge theory. In this paper, it is shown how their formalism can be
extended to include fermions. In the framework of Wilson's lattice QCD, we
define the Schr\"odinger functional by making use of the transfer matrix
formalism. Boundary conditions for the fermions arise naturally. We then take
the naive continuum limit of the action and show that no lattice peculiarities
are left over. The corresponding free Dirac operator has a unique self-adjoint
extension with purely discrete spectrum and no zero modes.
