Behcet's disease (BD) is a systemic chronic vasculitis of unknown aetiology characterised by mainly oro-genital ulcers. Renal involvement in BD is seen much less frequently than one would expect in a systemic vasculitis. Renal involvemenet in BD is mainly consisted of pyelonephritis, renovascular thrombosis, and stenosis, interstitial nephiritis, amyloidosis and glomerulonephritis.Glomerular involvement in BD is rare. There are occasional reports of glomerular involvement such as focal segmental glomerulonephritis. We describe a patient with Behcet's disease and focal segmental glomerulonephritis because of rare involvement and need renal biopsy.