Hydroxyethyl starch (HES) solutions are synthetic non-protein colloid solutions used to treat hypovolemia. However, their use is not free from the risk of allergic reactions. A 42-year-old male was scheduled to undergo aortic-iliac-femoral bypass surgery for the treatment of arteriosclerosis obliterans. He had no history of allergy. Two hours after the start of surgery, and within minutes after HES administration, facial erythema, hypotension and bronchospasm developed. HES infusion was discontinued under the estimation of anaphylaxis. The patient received phenylephrine, ephedrine, diphenhydramine and hydrocortisone with hydration. After restoration of vital signs, surgery was performed without complications.