A 38-year-old pregnant woman (19th week of pregnancy) complained of fatigue, cold inducible paresthesias, generalized edema and mild arterial hypertension. Her past medical history was notable for frequent episodes of polyarthralgia and positivity for rheumatoid factor. On admission, acanthocyturia and unselective glomerular-tubular proteinuria with 19 g/d were detected with a slight decrease in creatinine clearance. Rheumatoid factor was robustly elevated and a cryocrit of 1.5 vol%, caused by a so far unknown replicative hepatitis C, was detected. Renal biopsy yielded membrano-proliferative glomerulonephritis. During pregnancy, high-dose corticosteroid therapy was administered. Edema disappeared and blood pressure normalized under albumin substitution and low-dose furosemide application. However, Cesarian section became necessary due to placental insufficiency at 27 weeks of gestation. Thereafter, neither virus load, cryocrit nor proteinuria decreased significantly under a combined therapy with pegylated interferon-a and ribavirin. Thus, cryoprecipitate apheresis was initiated resulting in robust decreases of clinical complaints, viral load, cryocrit and proteinuria. Cryoglobulinemia with renal involvement caused by hepatitis C is difficult to treat due to limitations of immunosuppressive and anti-viral therapy. In our patient, cryoprecipitate apheresis was a safe and effective therapeutic addition to standard therapy.