A method of recovering unsupported fine catalyst from heavy oil comprises combining a slurry comprising unsupported fine catalyst in heavy oil with solvent to form a combined slurry-solvent stream. The combined slurry-solvent stream is filtered in a deoiling zone. A stream comprising unsupported fine catalyst and solvent is recovered from the deoiling zone. Unsupported fine catalyst is separated from the stream comprising unsupported fine catalyst and solvent. Filtering in the deoiling zone can comprise filtering the slurry and solvent through a cross-flow microfiltration unit, recovering a retentate stream of the cross-flow microfiltration unit, combining the retentate stream of the cross-flow microfiltration unit with solvent to form a combined retentate-solvent stream, and filtering the combined retentate-solvent stream through a cross-flow microfiltration unit.