Wild mushroom intoxication is an unusual cause of toxic ingestion in Europe. A great diversity of clinical symptoms may arise depending on the variety of wild mushrooms ingested. These initial symptoms are often non-specific, with frequent gastrointestinal symptoms, and have no direct correlation with the outcome. Therefore, management of mushroom poisoning and risk evaluation are a challenge for emergency clinicians. We retrospectively reviewed all cases of mushroom poisoning identified in the ED database spanning 11 years. Demographic and clinical data, time from consumption to symptoms, type of mushrooms, the number of patients presenting at the same time, treatment(s) provided, length of stay, discharge diagnosis, in-hospital mortality, and serious complications were evaluated. We identify 87 cases of mushroom poisoning. The most common symptoms are nausea and vomiting (71 cases, 82%), followed by diarrhea (68%), syncope (10%), abdominal pain (8%), and hallucinations (7%). Sixty-four patients (74%) exhibited early symptoms (appearance <6 h after ingestion) and 23 (26%) late symptoms (appearance >6 h after ingestion). Eleven patients (13%) required hospitalization over 24 h. Patients with late symptoms tended to have longer in-hospital lengths of stay. Only one patient had Amanita phalloides intoxication, with a favorable outcome. Thirty-eight patients (44%) were involved in cluster presentations. Mushroom poisoning is an unusual but potentially severe form of intoxication. Patients presenting with late-appearing symptoms (>6 h) are associated with a higher risk of A. phalloides intoxication, and therefore require specific investigation and management.