Membranous nephropathy (MN) is one of the most common causes of nephrotic syndrome (NS) in adults. It may be primary, usually mediated by IgG4 anti-phospholipase A2 autoantibodies or secondary to various other conditions. Guillain- Barré syndrome (GBS) has been associated with MN, but a cause and effect relation has not been proven. We present a case of concurrent development of GBS and severe NS, with renal biopsy demonstrating MN. IgG4 stain was negative, indicating that most likely, the MN was secondary and probably caused by the underlying GBS.