After immunization with A/New Jersey/76 and A/Victoria/75 influenza vaccines, 11 patients with systemic lupud erythematosus were serially evaluated for changes in disease activity, serologic abnormalities, and their capability to generate specific antibodies. One patient, with active disease, developed a diffuse, proliferative glomerulonephritis. None of the other patients or control subjects had significant local or systemic side effects. Significant levels of antibodies were generated to A/New Jersey/76 in eight of the 11 patients and in seven of eight control subjects and to A/Victoria/75 in seven of 11 patients and five of eight control subjects. The geometric mean responses of both total and IgG antibodies to each viral antigen were no different in patients with systemic lupus erythematosus than in control subjects. In patients with stable systemic lupus erythematosus, immunization with killed influenza viral vaccine appears to be safe and effective.