High resolution electron microscopy, HREM, of(110)(Nb)parallel to(<11(2)over bar 0>)(Al2O3) interfaces grown by molecular beam epitaxy, MBE, has confirmed that the interface is semicoherent for the films investigated, and that for this orientation misfit dislocations occur at the interface both with and without stand-off from the interface. The dislocation networks have been identified by conventional transmission electron microscopy, CTEM, to be composed of misfit dislocations with a Burgers vector of 1/2[111], which corresponds to the Burgers vector of bulk dislocations in Nb.