INTRODUCTION: Datura stramonium, also known as jimson weed, is a hallucinogenic plant that is increasingly used by adolescents. It is important to know how the substance is used and what the clinical signs of intoxication are to develop recommendations to avoid potentially serious side effects. CASES: We reviewed the medical files of two adolescents admitted to our university hospital after voluntary Datura intoxication. Both patients had an anticholinergic syndrome and needed in-patient surveillance, one for 8 and the other for 24 hours. One patient complained of difficulty in visual accommodation, which lasted a few days, and the other reported amnesia about the episode for a few months. DISCUSSION: Diverse indicators suggest that increasing numbers of young people are using "natural" hallucinogenic substances, most often during group initiation sessions. Because there is no reliable biological marker for the substance, diagnosis is clinical. Symptoms can persist beyond the acute phase that brought the patients to medical attention. Fortunately, the unpleasant memory of the experience generally prevents consumers from repeating it. CONCLUSION: Its easy access and the absence of legislation make Datura a tempting choice of psychoactive substance for sensation-seeking young people. To reduce its risks, professionals should recommend that Datura be used only if a non-user is present, that it not be mixed with any other drugs, and that help should be sought at the first signs of apparent intoxication. Other cases must be studied before we can determine the factors that contribute to and reduce the risk of life-threatening intoxication.