We observed six cases of patients in a dialysis programme who were apparently intoxicated by ingestion of star fruit. After ingestion of 2-3 fruits or 150-200 ml of the fruit juice, the six patients, who had previously been stable in a regular dialysis programme, developed a variety of symptoms ranging from insomnia and hiccups to agitation, mental confusion and (in one case) death. In preliminary investigations to characterize the hypothetical neurotoxin in the fruit, an extract, when injected intraperitoneally or intracerebroventricularly in rats, provoked persistent convulsions of the tonic-clonic type. It appears that star fruit (Averrhoa carambola) contains an excitatory neurotoxin. Patients with renal failure on conservative or dialysis treatment should be dissuaded from ingestion of the fruit.