Translation from Spanish to English by T.A. Zuur and The Language Workshop Received: 29-04-11 Accepted: 02-08-11 Abstract Reactivation of hepatitis B virus (HBV) replication in patients undergoing immunosuppressive therapy may precipitate fl are ups of chronic HBV infections. We present the case of a 57 year old female who had suffered six weeks of abdominal discomfort, dyspepsia, and joint paint. After three weeks of therapy with prednisolone, methotrexate and chloroquine, the patient developed ascites and increased serum levels of AST and ALT. Chronic hepatitis B infection was confi rmed by liver biopsy. Conclusion: Tests for hepatitis B should be conducted before immunosuppressive therapy is begun. Corticosteroids and other immune suppressors can reactivate hepatitis B and produce severe clinical symptoms and can put the patient’s life at risk.