A 63-year-old man with chronic hepatitis C and persistently normal alanine aminotransferase levels was treated with peginterferon alpha-2a (180 microg weekly) and ribavirin (800 mg daily). Hepatitis C virus-ribonucleic acid was negative at week 4. After 12 weeks of therapy, haemoglobin levels had decreased by 3.5mg/dL, and he developed a syncope episode with electrocardiographic signs of myocardial ischaemia. Antiviral treatment was stopped and the ischaemia-like electrocardiographic changes resolved completely within 2 months. Eight months later, because of the previous rapid virological response and patient motivation, he was treated again with peginterferon and ribavirin. Baseline and weekly electrocardiographic recordings were obtained during treatment. At week 4 hepatitis C virus-ribonucleic acid was negative. At week 8, when the haemoglobin levels had decreased by 3.4 mg/dL, the patient developed the same ischaemia-like changes that occurred during the previous treatment. Antiviral therapy was stopped and the electrocardiographic ischaemia-like changes disappeared after 1 month. The patient neither had a history of previous cardiovascular diseases, nor evidence of current disease at myocardial scintigraphy. However, a coronary microvessel spasm, possibly related to drug-toxicity and/or anaemia could not be excluded. This case indicates the need of strict electrocardiographic monitoring in elderly patients undergoing treatment with peginterferon and ribavirin.