Hepatitis B virus (HBV) vaccination has been implicated as a potential trigger for autoimmune diseases but there are no prospective studies in lupus. We therefore assessed prospectively the safety and efficacy of immunization with recombinant DNA HBV vaccine (Euvax B; LG Life Sciences) in systemic lupus erythematosus (SLE) patients. Twenty-eight consecutive inactive SLE patients [Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) <4], age between 18 and 50 years and negative serology for HBV, were selected. Exclusion criteria were prednisone >/=20 mg/day and immunosuppressive drugs. Clinical and laboratorial assessments were obtained at study entry and one month after the three doses. In addition, a previous one year evaluation was performed using a standard electronic protocol. The mean age was 34 +/- 7.7 years and disease duration was 10.4 +/- 6.7 years. An adequate seroconversion was achieved at the end of the study (93%), although a lower frequency after the first (4%) and second dose (54%) was observed. No significant change in mean SLEDAI score was detected after each dose throughout the study (0.14 +/- 0.52 versus 0 versus 0.61 +/- 1.66 versus 0.36 +/- 1.34, P = 0.11). Reinforcing these findings, the 11% flares during vaccination was similar to the 21% observed in the previous year (P = 0.46). Furthermore, the mean prednisone dose at study entry was comparable to the end of the study (2.86 +/- 3.06 versus 4.64 +/- 8.25 mg/day, P = 0.32). In addition, the frequency of immunosuppressive therapy during the vaccination period (11%) was alike to the 14% observed in the previous year before entry (P = 0.66). Hepatitis B vaccination was safe in inactive SLE patients with an adequate vaccine response rate.