Patients with thalassemia may complain of numbness and weakness of the lower extremities. The aim of the study was to document whether these patients suffer from a polyneuropathy and to determine any contributing factors for the development of neuropathy.We examined 30 patients with thalassemia major and intermedia, clinically and electrophysiologically. We correlated these findings with demographics, blood status, and treatment and compared electrophysiologic data with 30 age- and sex-matched normal subjects or historical controls.We found that 78% of thalassemic patients suffered from a mild sensory polyneuropathy. The neuropathy seemed to be worse in the intermedia type. Thalassemic patients who received blood transfusions and deferoxamine had better nerve function than those who did not, irrespective of the dose of deferoxamine. The neuropathy was worse for older patients, irrespective of sex. The hemoglobin level, and the fact that some patients underwent splenectomy, did not affect the status of the patients' nerves.Patients with thalassemia may suffer from a sensory polyneuropathy especially as they grow older and if they are not optimally treated.