OBJECTIVE To investigate the hepatotoxic effects of accidental intravenous diethylene glycol (DEG.) poisoning in patients with liver disease. METHODS Clinical data and liver function results were obtained from 64 patients with liver diseases who had been accidentally treated with diethyl glycol-contaminated agent and 45 cases with hepatorenal failure. The hepatotoxic effects of diethylene glycol DEG on the patients with liver diseases were assessed by multivariable logistical regression analysis. RESULTS Of the 64 cases with liver diseases, 15 cases (23.4%) developed toxic presentations following the accidental administration of DEG. All affected cases were male. Twelve of the 15 poisoned patients (80%), died within 7 days of exposure to DEG. The most common clinical manifestations included kidney damage, renal failure, metabolic acidosis, and nerve system disturbances. The intravenous administration of DEG resulted in only mild liver function impairment. In terms of risk factors, both gender (r = 4.266, P less than 0.05) and the severity of jaundice prior to DEG administration were related to the occurrence of toxin-induced renal failure (r = 7.640, P less than 0.01). CONCLUSIONS DEG may worsen liver damage in patients with liver diseases.