Well known clinical syndromes can be produced by overdose with more commonly ingested substances such as opiates or tricyclic antidepressants. A case of a much more unusual syndrome presenting to the accident and emergency department resulting from overdose with a combination of tablets is reported. The clinical presentation of serotonin syndrome and its management are described. This resulted from acute ingestion of paroxetine, a selective serotonin reuptake inhibitor, and moclobemide, a monoamine oxidase inhibitor.