Of 1,500 different types of Norwegian mushrooms, 60-100 are considered poisonous. Fatal intoxications occur very infrequently. Lack of knowledge of picking and preparing mushrooms and accidental or deliberate consumption are recognised causes of mushroom poisoning. Delayed onset of symptoms (> 5-6 hrs) indicates serious poisoning, and these patients must be admitted to hospital. Cytotoxic toxins (e.g. amatoxin, orellanin) cause serious damage to the visceral organs (liver, kidney) and require intensive treatment, including hemoperfusion. Neurotoxic toxins may cause dramatic, but less harmful peripheral or central symptoms affecting the peripheral and central nervous systems, including hallucinations. Some mushrooms cause gastroenteritis of low clinical significance within a few hours after consumption. Interaction between mushrooms and alcohol may lead to a disulfiram-like effect. Induced vomiting and activated charcoal are important initial therapeutic measures. The precise history of the patient and the collecting of mushroom remnants, including vomitus, may help to identify the particular mushroom. In Norway, the National Poison Information Centre may be contacted for further advice.