Abstract: A 10-years-old male Maltese dog was presented with severe vomiting, diarrhea, bradycardia and respiratory difficulty, after the ingestion of a poisonous wild mushroom (Inocybe fastigiata). No remarkable abnormalities in complete blood cell counts and serum biochemistry were observed except hemoconcentration. The dog was treated with gastric lavage, anti-cholinergics (atropine) and fluid therapy (0.9% saline) for 48 h. The dog was released after 48 h of emergency treatment. This is the 1st case report related to poisoning from Inocybe fastigiata mushroom in a dog.