The slow, subcutaneous infusion method of immune human serum globulin replacement was used during pregnancy in a woman with common common variable immunodeficiency and splenectomy. Since this method allows high doses of immune human serum globulin to be given with little pain or morbidity, as much as 20 mL/day of immune human serum globulin was tolerated, normal serum IgG levels, were maintained, and the patient was free from serious infection throughout her pregnancy. The infant also had a normal IgG level at birth and had no evidence of intrauterine infection. This may be a preferable route of immune human serum globulin administration, especially during pregnancy and in other situations where high-dose therapy is advantageous.