Abstract: An intravenous immune globulin preparation having at least 99% pure globulin protein and an anticomplement activity of less than 0.10 C'50 units/mg IgG prepared by: precipitating impurities from Cohn Fraction II in an aqueous-alcohol medium at defined temperature and pH, removing the precipitated impurities, stabilizing the diluted solution with albumin, concentrating the solution and removing the alcohol therefrom. Also prepared by this method, an intravenous, hyperimmune globulin preparation having increased antibody titers to sixteen serospecific strains of Pseudomonas aeruginosa.