A 16-year-old white boy with acute systemic lupus erythematosus (SLE) who presented with chorea and florid retinopathy died in renal failure three months after diagnosis. Pathological studies revealed two types of lesion in both the cerebral and ocular vessels. Some meningeal and choroidal vessels showed a typical vasculitis with fibrinoid necrosis, whereas other meningeal and retinal vessels were occluded by amorphous hyaline material in the absence of vasculitis.