Serotonin syndrome, a potentially fatal condition of serotonergic hyperstimulation, has been characterized by diagnostic criteria that include at least three of the following: mental status changes (confusion or hypomania), restlessness, myoclonus, hyperreflexia, diaphoresis, shivering, tremor, diarrhea, and incoordination (1). Nefazodone has previously been implicated in two cases of serotonin syndrome, one with paroxetine (2) and one with valproic acid (3), whereas trazodone has been implicated in combination with buspirone (4), paroxetine (5), fluoxetine (6), and amitriptyline with lithium (7). To our knowledge, this is the first report of serotonin syndrome associated with the combination of nefazodone and trazodone.