A 28-year-old Japanese woman developed fever, leg edema, purpura, and abdominal pain during the puerperal period, showing nephrotic syndrome with microscopic hematuria. At first she was thought to have Henoch-Shönlein purpura nephritis and was given steroids at another hospital. Because anasarca and massive urinary protein excretion developed, she was referred to our hospital. Renal biopsy specimens showed endocapillary proliferative glomerulonephritis with massive IgA and C3d deposition along the capillary loops and in the mesangium. A bacteriological study detected methicillin-resistant Staphylococcus aureus (MRSA) in cultures of vaginal secretions, urine, stool, and pharyngeal mucus samples. Based on the diagnosis of MRSA nephritis, anti-MRSA therapy with antibiotics was started, and MRSA became negative for each culture, and urinary protein decreased. Two months after the first renal biopsy, a second renal biopsy was performed, which revealed feeble endocapillary proliferation with mild IgA and C3d deposition in the mesangium. This case showed that the delivery procedure can cause MRSA nephritis after MRSA infection, and that steroid therapy should be avoided in the early phase of this type of nephritis.