Résumé : This paper reports on a five year old girl suffering from chronic salmonella infection complicated by hypergammaglobulinemic purpura and mixed cryoglobulinemia. In spite of various and vigorous treatment, the child died. Intermediate complexes characteristic of the hypergammaglobulinemic purpura of Waldenstroem were isolated. A mixed cryoglobulinemia was also demonstrated and studied. Impairment of phagocytosis in the presence of the cryoglobulin was demonstrated. It is suggested that the cryoglobulin acted as an immune complex inhibiting both phagocytosis and cellular immunity and was thus responsible for the persistence of the salmonella infection and for its unusual manifestations and its lethal outcome despite vigorous treatment.