Hydroxyethyl starch (HES) is a macromolecular preparation that has been used as a volume expander since 1991. Renal toxicity of high-dose HES is now well recognized but potential renal toxicity of low-dose HES is poorly documented. Acute renal toxicity of cyclosporin A (CyA) may be responsible for osmotic nephrosis-like lesions. We report here the case of a 30-year-old male who developed cirrhosis due to hepatitis B and delta viruses and polymyositis. Polymyositis was treated with CyA, prednisone and plasma exchanges using low-dose HES as the replacement fluid. Renal insufficiency occurred with biopsy-proven osmotic nephrosis-like lesions, considered to be secondary to HES infusions and/or CyA.