We retrospectively and prospectively reviewed the incidence of stroke in 105 patients with systemic lupus erythematosus (SLE). Stroke occurred in 14 (15%) of 91 consecutive patients with documented SLE; nine (64%) of the 14 had multiple cerebral infarcts. Factors associated with stroke and the frequency of stroke were systemic thrombosis (30%), elevated partial thromboplastin time (36%), spontaneous abortion (50%), age over 60 years (57%), transient ischemic attacks (57%), previous stroke (64%), and cardiac valvular disease (86%).