Chronic hepatitis B is considered a major public health problem, and its treatment entails increasing health budget expenses with high-cost drugs covered by Unified National Health System. The objective of this study was to compare the efficacy of interferon (conventional; pegylated - PEG2a) and lamivudine (LAM) for the treatment of chronic hepatitis B through a systematic review, selecting randomized, controlled clinical trials identified in PubMed and LILACS. Target outcomes were virological, biochemical, and histological response, seroconversion, and adverse effects. The review selected 35 articles. Presence or absence of HBeAg and pre-treatment alanine aminotransferase (ALT) levels were considered important factors in the initial therapeutic indication. Treatment with conventional interferon enables lasting disease inactivation and can result in HBsAg seroconversion. PEG2a showed better efficacy than interferon and LAM and similar side effects to interferon. LAM presents advantages such as its sensitivity in the HbeAg-negative phenotype, while its main disadvantage is the development of resistance.