The previously reported detrimental effects of pregnancy on the course of membranoproliferative glomerulonephritis type II (MPGN type II) are limited and are usually considered to be mild. Based on these reports, a 19-year-old female with the diagnosis of MPGN type II who had stable renal function (creatinine 0.9 mg/dl) and a mild nephrotic syndrome with hypertension for 5 years of close follow-up was advised to complete her pregnancy. After a full-term pregnancy, complicated only by moderate nephrotic syndrome, a healthy female infant was born. Two weeks after delivery, the patient presented with acute renal failure and malignant hypertension, without evidence of hemolysis of hepatic failure. Immunologic parameters, including, C3, C4, antinuclear antibodies, circulating immune complexes as well as antibodies to glomerular basement membrane antigen and tubular basement membrane antigen were negative. Peritoneal dialysis was initiated and a renal biopsy was performed which showed MPGN type II with 50% crescents. Despite pulse therapy with methylprednisolone, renal function did not improve, resulting in the need for chronic dialysis. Although no specific nephritogenic mechanism was shown, the course of this patient should be considered when counseling female patients with MPGN type II, regarding the possibility of pregnancy exacerbating their disease, or resulting in rapidly progressive renal failure.