Three hundred seventeen patients with toxic oil syndrome caused by ingestion of denatured rapeseed oil were followed up after one year. Total mortality for the 317 patients was 4.4%. After 12 months, 3.2% of the surviving patients have a severe motor neuropathy, 52.9% are asymptomatic, and the remaining 39.4% have mild residual myalgia. The cause of death in seven patients during the acute phase of toxic oil syndrome was respiratory failure due to interstitial pneumonitis with cerebral edema. The death of five patients in the second phase was due to motor neuropathy that involved respiratory muscles and was complicated by aspiration pneumonia.