The resolution gap between macromolecular crystallography and electron microscopy continues to decrease. Recent advances in specimen preparation, instrumentation and computational power have allowed accurate structure determination of larger macromolecular complexes by crystallography and/or by electron microscopy on cryovitrified samples. New possibilities in structural biology have opened up and new challenges are faced to further reduce the resolution gap. A workshop at the Lorentz Center, Leiden, The Netherlands, which took place in May 2008, was organized to push further the limits of both complementary techniques through improved computational methods.