This paper describes two different cases of acute suicidal arsenic trioxide intoxication. Case no 1. A 38-year-old man, alcohol abuser, who ingested 4-5 g dental paste, which corresponds to 2.2-2.7 g of pure arsenic trioxide, developed gastritis with vomiting and abdominal pain, but without diarrhea. No cardiovascular collapse or renal failure were observed. The patient developed also symptoms of central nervous system injury (minor left paresis) and transient hepatic impairment. A head CT revealed no pathological changes in the brain. Hepatic disturbance recovered in a few days and the patient could be discharged on the 12 day. Case no 2. A 57-year-old man, who ingested few grams of pure arsenic developed vomiting, abdominal pain and severe diarrhea. Cardiovascular collapse as a result of intravascular volume depletion, vasodilatation and myocardial dysfunction was observed. The patient died on the first day of hospitalization. In both cases treatment included gastric lavage, BAL therapy, haemodialysis and supportive measures.