Acute hepatitis B infection often features gastrointestinal symptoms and jaundice, as well as elevated transaminase levels and the presence of hepatitis B surface antigen and immunoglobulin M antibodies to hepatitis B core antigen. More than 95% of adults clear an acute infection spontaneously. Chronic hepatitis B infection is diagnosed when hepatitis B surface antigen is present for at least 6 months. Evaluation of chronic cases includes a family history of hepatocellular carcinoma, assessment of liver function and fibrosis risk, and serologies for viral coinfections and immunity. The goal of therapy is to reduce the risk of cirrhosis, hepatocellular carcinoma, and liver-related mortality. Oral nucleoside/nucleotide analogues are well tolerated and have a high barrier to resistance, which enables long-term use. With current therapies, functional cure (loss of hepatitis B surface antigen) is uncommon. Nucleoside/nucleotide analogue therapy is warranted when a patient has an elevated alanine transaminase level and a hepatitis B DNA measurement more than 2,000 IU/mL, or cirrhosis with detectable virus. Prophylactic viral suppression with oral nucleoside/nucleotide analogues is recommended during immunosuppression. Patients with cirrhosis or increased risk of cirrhosis should receive surveillance for hepatocellular carcinoma with right upper quadrant ultrasonography and serum alpha-fetoprotein testing every 6 months.