Hepatitis B virus (HBV) reactivation with imatinib, a tyrosine kinase inhibitor, has been reported in chronic myeloid leukemia. Nilotinib is a more potent second generation tyrosine kinase inhibitor and it inhibits the Src-family kinase LCK and hamper proliferation and function of CD8 (+) T lymphocytes. CD8 (+) T lymphocytes are the main cellular subset responsible for viral clearance in patients with HBV infection. We report a case of HBV reactivation under treatment with nilotinib. Fatal HBV reactivation is not usually related to death in chronic myeloid leukemia patients who have an expectation of longevity with well-tolerated oral drugs. Thus, screening for latent chronic HBV infections including assessment of hepatitis B surface antigen (HBsAg), antibody to hepatitis B core antigen (anti-HBc antibody) and antibody to hepatitis B surface antigen (anti-HBs), especially at countries with intermediate and high prevalence of HBsAg is warranted. Treatment with nucleoside analogs and close monitoring may be life-saving in this context.