Forty patients with systemic lupus erythematosus randomly received inactivated bivalent (A/NJ and A/Victoria) influenza vaccine or saline in a double-blind study. During 20 weeks of follow-up, no deterioration in major organ function or increase in disease flares was observed in the immunized group as compared with the group that received saline. Preimmunization antibody titers to A/Victoria were lower in the 40 patients with lupus erythematosus than in age-matched control subjects. Response to immunization, as measured by serum antibody titers, was also lower in the patients with lupus erythematosus, indicating that immune responses must be evaluated on an individual patient basis. Nevertheless, influenza vaccination can be safely carried out in patients with systemic lupus erythematosus.