The invention relates to a process for recovering ruthenium from a used ruthenium-comprising catalyst which comprises ruthenium as ruthenium oxide on a support material which is sparingly soluble in mineral acid, which comprises the steps: a) the catalyst comprising ruthenium oxide is treated in a stream of hydrogen, with ruthenium oxide present on the support being reduced to metallic ruthenium; b) the reduced catalyst from step a) comprising metallic ruthenium on the support material is treated with hydrochloric acid in the presence of an oxygen-comprising gas, with the metallic ruthenium present on the support being dissolved as ruthenium(III) chloride and being obtained as ruthenium(III) chloride solution; c) if appropriate, the ruthenium(III) chloride solution from step b) is worked up further.