We present the case of an 82-year-old man admitted to our hospital for muscle weakness. He was under simvastatin 20 mg per day and was given pulse itraconazole therapy 8 days before the onset of symptoms for onychomycosis. He developed severe rhabdomyolysis inducing an acute renal failure necessitating renal replacement therapy. He eventually fully recovered. Given the possible concurrent use of simvastatin and itraconazole, awareness of this potential interaction is clinically important.