We observed retinal vasculitis in seven patients with clinical and serologic evidence of Borrelia burgdorferi infection. Three patients presented with abrupt loss of vision due to acute retinal vasculitis. Funduscopy demonstrated engorged veins, hemorrhages, perivenous infiltrates and retinal white spots. Fluorescein angiography showed leakage from the veins, from the white spots and from the optic disc. Moreover arterial occlusions were observed in two patients. Four patients had signs of chronic uveitis with vitritis, cystoid macular oedema and retinal vasculitis, which was associated with neovascularization and vitreous hemorrhage in one patient, and with optic neuritis in another patient. Six patients received antibiotic treatment and three patients received systemic corticosteroids. Marked improvement in the three acute retinal vasculitis cases occurred within several weeks, the fundus changes disappeared in another few months, and no recurrences were observed. The final visual acuity was excellent in these patients, although optic disc pallor and visual field loss persisted in one case. In the four patients with chronic uveitis visual blurring improved following antibiotic treatment and the retinal vasculitis and vitritis slowly regressed. The proliferative retinopathy of one patient required panretinal laser treatment.