Process for separating and recovering rhodium and/or iridium from the other precious metals (Pd, Pt, Ru, Os, Au, Ag), according to which a solution containing the precious metals in any form is treated for a time between 15 minutes and 10 hours with carbon monoxide in the presence of a quantity of water or primary or secondary alcohols at least equal in weight to the total quantity of precious metals present, the crystalline precipitate which forms, and which contains all the noble metals except Rh and Ir in a state of high purity is separated and the Rh and/or Ir are recovered practically totally from the solution.