We describe severe sertraline intoxication in a child after accidental ingestion. Sertraline is a new antidepressant that has potent and selective inhibition of neuronal serotonin reuptake. Drug company-sponsored research has suggested little toxicity for this compound. Our patient exhibited prolonged tachycardia, hypertension, hallucinations, coma, hyperthermia, tremors of all extremities, and skin flushing. Clinicians should consider the possibility of serotonin syndrome among patients with similar clinical features and a recent history of sertraline or other serotonergic agent ingestion.