Hydroxychloroquine, a quinoline compound, rarely causes ototoxicity. According to the few reports in existence, hydroxychloroquine-induced ototoxicity occurred following prolonged therapy in adult patients with rheumatoid arthritis and lupus erythematosus. We report a case of unilateral sensorineural hearing loss in a 7-year-old girl with idiopathic pulmonary haemosiderosis, after 2 years of hydroxychloroquine treatment. Sensorineural hearing loss has previously been reported with hydroxychloroquine treatment, but this is the first report in a child and associated to idiopathic pulmonary haemosiderosis and has the characteristic of being unilateral. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved.