The association of renal vein thrombosis and membranous glomerulopathy in native kidneys has been well documented. However, this association has only occasionally been described following renal transplantation. A review of 693 renal transplant recipients revealed 77 (11%) in whom persistent, heavy proteinuria (>2 g/24 hr) developed. Renal histology was available in all 77 patients. A diagnosis of membranous glomerulopathy was made in 7 patients. Two further cases were added on the basis of biopsy findings—1 patient had a protein excretion of 1.7 g/24 hr, the other had microscopic hematuria and red cell casts in the urine. Renal venography was performed in 4 cases. The decision to perform venography was based on clinical criteria (thrombophlebitis or marked edema of the leg on the side of the allograft), and/or histological criteria (associated interstitial edema and venous congestion). Renal vein thrombosis was present in 2 patients. Three of the 9 patients had membranous glomerulopathy as the cause of their end-stage renal disease; 2 of these patients had received kidneys from living-related donors. Four of the patients were classified as having de novo membranous glomerulopathy on the basis of having a different cause for their end-stage renal disease. Two patients were classified as having unspecified membranous glomerulopathy; both of these patients had had chronic glomerulonephritis, but there was lack of characterization of the original glomerular disease. Seven of the 9 patients continued to have stable allograft function 1–12 months after the diagnosis of membranous glomerulopathy was made in the renal allograft. The remaining 2 patients both had associated renal vein thrombosis; 1 had progressive deterioration of renal function and returned to dialysis 24 months after the diagnosis of membranous glomerulopathy had been made, while the other died of unrelated causes 27 months after the diagnosis had been made.