The growth of new therapeutic options and practices increases the risk of hepatitis B virus (HBV) reactivation in patients with haematologic malignancies and/or patients undergoing haematologic stem cell transplantation (HSCT). To provide a systematic review supporting recommendations for prevention, monitoring, prophylaxis and therapy of HBV reactivation in patients with haematologic malignancies and HSCT. The systematic review was based on a strategy using PubMed and the Cochrane Library searching literature published from 1991 to December 31, 2016. PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines were followed. Randomized control trials, prospective and retrospective cohort studies. Cochrane Risk of Bias Tool and Newcastle Ottawa Quality Assessment Scale. Forty-two studies of fair or good quality were included in this systematic review. The following main results were obtained: haematologic patients should be screened for HBV before chemotherapy; HBV DNA levels should be monthly monitored in all HBV-positive patients not receiving prophylaxis; hepatitis B surface antigen (HBsAg)-positive haematologic patients and patients undergoing HSCT should receive prophylaxis and third-generation HBV drugs should be provided; and anti–hepatitis B core protein–positive lymphoma patients and patients who underwent HSCT should receive antiviral prophylaxis. A higher quality of evidence is needed. However, the level of evidence was sufficient to support the recommendations published in this issue of the journal.