Abstract. Purpose: To report the result of ranibizumab administration in an eye with ocular ischaemic syndrome. Methods: Fluorescein angiography, ocular pneumoplethysmography and retinal vessel calibre measurement. Results: An 85-year-old man with ocular ischaemic syndrome demonstrated vision loss, retinal vessel calibre constriction and profound retinal ischaemia after intravitreal ranibizumab. Conclusion: We advise against the use of intravitreal vascular endothelial growth factor inhibitors in eyes with ocular ischaemic syndrome.