Diethylene glycol (DEG) intoxication resembles that of ethylene glycol, with progressive inebriation, anion gap metabolic acidosis, renal failure, coma and death. DEG is oxidized by alcohol dehydrogenase (ADH) to more toxic byproducts, thus blockade of ADH might be beneficial. Triethylene glycol (TEG), also metabolized by ADH, is less toxic. A young female suicidally ingested DEG and TEG, presenting in metabolic acidosis with coma. Given 4-methylpyrazole (4-MP), an ADH inhibitor, the acidosis resolved, the patient recovered and was discharged without sequelae. 4-MP, if supported by further studies, may be useful in DEG poisoning.