Therapy of hepatitis B virus (HBV)-associated poly-arteritis nodosa is still evolving. Here we report a successful treatment with a short-term steroid administration in combination with a-interferon and lamivudine and a complete sequence analysis of the HBV genome. A 58-year-old man presented with the symptoms of mononeuritis multiplex associated in time with the onset of highly replicative hepatitis B. Polyarteritis nodosa was confirmed by biopsy. During an initial course with alpha-interferon and prednisolone no clinical improvement or hepatitis B virus seroconversion was observed. After addition of lamivudine to the protocol with fast tapering of prednisolone, HBV DNA fell to undetectable levels within 1 month and liver transaminases normalized. After 6 months of treatment HBeAg seroconversion took place, followed by HBsAg seroconversion 2 months later. Clinical symptoms of polyarteritis improved. No relapse of polyarteritis or hepatitis B was seen during the follow up of 9 months. Complete sequence analysis of the HBV genome revealed 6 nucleotide mutations but none in a relevant antigenic epitope. The present protocol of short-term prednisolone administration combined with alpha-interferon and lamivudine was effective for the treatment of HBV-related polyarteritis nodosa and may be a promising new therapeutic approach.