Summary. Henbane, Hyoscyamus niger, is a hallucinogenic plant, widely spread and easy accessible, which contains anticholi- nergic substances. Ingestion, intentional or accidental, can provoke serious worsening of psychophysical state and can cause even death. Intoxication resembles the one with atropine. Symptoms like mydriasis, tachycardia, arrhythmia, agitation, convulsion and coma can appear. Diagnosis is made by clinical symptomatology and history. Therapeutic acts include stomach lavage, supportive therapy and physostigmine as a specific antidote. Prognosis is usually good.