A case of purpura hyperglobulinaemica of Waldenstrom is reported. Immunofluorescence of skin and subcutaneous tissue using monospecific fluorescein-tagged anti-human IgA, IgG, IgM and complement showed deposition of IgA in the walls of intradermal vessel in affected skin. It is suggested that these findmgs help in the elucidation of the pathogenesis of the purpura.