The hepatitis B virus (HBV) and the hepatitis C virus (HCV) affect approximately 400-500 million individuals worldwide. Both infections are characterised by a significant morbidity and mortality: chronic hepatitis B and C may evolve towards the development of cirrhosis and primary hepatocellular carcinoma. During the last two decades, several new antivirals have been developed that are active against HBV and HCV, allowing sustained cure rates in a significant proportion of patients. All these drugs have side effects, which may represent a major barrier to achieve cure in many patients in need. I will review the most common adverse events reported during the therapy of chronic hepatitis B and C, with some recommendations for proper management.