Primary antibody deficiencies are the most common forms of primary immunodeficiencies. Substitution therapy with polyvalent immunoglobulins has been established as the standard therapy for antibody deficiencies for several decades. Until now mainly intravenous immunoglobulins (IVIG) have been used in Germany, and the majority of patients receive treatment in hospital outpatient clinics. In recent years subcutaneous administration of immunoglobulins (SCIG) has been developed which is administered as home self-infusion. Studies indicate no significant differences in immunoglobulin substitution therapy between SCIG and IVIG concerning outcome. We carried out a cost-minimization analysis to compare the two treatment alternatives in Germany. Under base case assumptions the treatment with SCIG is cost saving from the perspective of the German statutory health insurance. The main cost drivers are IVIG and SCIG; the incremental cost of SCIG compared to IVIG is most sensitive to changes in the immunoglobulin price and changes in the body weight of the patient.