Although generally well tolerated there have been a number of reports of acute deterioration in renal function with the use of intravenous immune globulin (IVIG). It is of generally limited duration and is self-limiting. We for the first time have described a patient with multiple myeloma and normal renal function who developed chronic renal failure shortly after IVIG treatment in a patient with no pre-existing renal disease. We would therefore recommend the cautious use of IVIG in patients with normal renal function or with pre-existing renal disease. Renal function should also be assessed both prior to and after application of IVIG.