Lamivudine resistance develops in up to 80% of patients with chronic hepatitis B (CHB) after 5 years of treatment. Cross-resistance between nucleoside/nucleotide analogues limits management options in these patients. To investigate the role of pegylated interferon-α2a as rescue therapy in these patients, the efficacy and safety of pegylated interferon-α2a between treatment-naive patients and lamivudine-resistant patients with hepatitis B e antigen (HBeAg)-positive CHB were compared.