The invention relates to a novel, industrial-scale process for the purification of gamma-immunoglobulins (IgG) starting from plasma or fractions thereof. The method involves two chromatographic steps, i.e. a cation exchange capture chromatography, and then a polishing anion exchange chromatography, ensuring a highly purified end product, which contains no aggregates, and high yields. The process also involves a virus inactivation step by means of a solvent/detergent treatment to inactivate the viruses with a lipid envelope, and a virus removal step by nanofiltering to ensure the removal of the non-enveloped viruses.