The authors report and describe 4 deaths after apparent coadministration of MDMA and the monoamine oxidase inhibitor (MAOI) moclobemide. Blood and urine in all cases were analyzed for the presence of ethanol and 100 drugs, including MDMA and moclobemide. Blood was also examined for the presence of 150 drugs, including MDMA and moclobemide. Cases consisted of three males (ages 18, 19 and 23) and one female (age 18). Blood MDMA in Case 1 (18-year old female) was 1.6 mg/1, and moclobemide levels were 2.3 mg/l. Blood MDMA in case 2 (23-year old male) was 2.0 mg/l, and moclobemide was 2.1 mg/l. In Case 3, blood MDMA was 0.15, MDA was 0.05 mg/L, and moclobemide levels were 7.9 mg/L. MDMA levels in Case 4 (19-year old male) were 2.1 mg/L, MDA levels were 0.05 mg/L, and moclobemide was 6.5 mg/L. Except for Case 4, who had taken 10 tablets of unknown dosage, the researchers were unable to learn the number of tablets taken by the other individuals before death. Body temperature was only recorded in Case 3 (43 deg. C). Cases 1 and 4 ingested ethanol (alcohol) before or during ecstasy consumption, and traces of a number of drugs were detected in Case 3, including several benzodiazepines, dextromethorphan and morphine. Confusion, high body temperature, and some signs of widespread visceral congestion (presumably referring to disseminated intravascular coagulation, DIC) in Case 4 are interpreted as signs of serotonin syndrome resulting from combining MDMA with an MAOI. Moclobemide was not prescribed to any of the individuals. The authors conclude that these four individuals combined moclobemide with MDMA either in the mistaken belief that it was similar to a serotonin uptake inhibitor and would have protective effects, or because they believed it would enhance their drug experience. All four fatalities occurred in the same region of Finland (Western Finland), and two cases occurred within a short time period, suggesting that the individuals may have been acting in response to a specific rumor or story.