Quinine is widely used in the treatment of nocturnal leg cramps in the elderly, despite the limited evidence of efficacy. The potential toxicity in an overdose is well known and associated with severe ocular complications. We report a 32-year-old woman with quinine induced permanent bilateral visual loss after ingesting 8.4-12.6 grams of quinine over a period of three weeks. We discuss the use of quinine as an over-the-counter drug.