One of the extra-hepatic manifestations of hepatitis B virus is polyarteritis nodosa (PAN). It may involve medium- and small-sized arteries in any organ. Concurrency of these two diseases may be life threatening and both should be treated. Herein, we report on a patient with severe PAN and high hepatitis B virus load. The patient was an 18-year-old boy with multiple progressive wounds in the skin, referred to our center. The preliminary evaluation showed vasculitis in the skin biopsy compatible with PAN. He was treated with low dose prednisolone and lamivudine for three years. However, his condition got worse and ulcers on his leg became life threatening. The viral load was 17,000,000 copy/mL. The wound developed superimposed resistant bacterial infection. The patient was then treated with two antiviral drugs—lamivudin 100 mg/day plus adefovir 10 mg/day—and high dose cyclophosphamide (750 mg, once a month) and prednisolone (60 mg/day for one month). After six months of treatment, viral load decreased to 100,000 copy/mL and wounds healed. We concluded that high viral load of hepatitis B virus may play an important role in the severity of PAN. We recommend combination therapy with two antiviral agents with high dose of immunosuppressive drugs until both the diseases resolve significantly.