Botulism is a rare but potentially life-threatening disease caused by Clostridium botulinum neurotoxin. In Finland only a few cases have been diagnosed during the past ten years but mild cases may be underdiagnosed. The diagnosis of botulism is clinical. Patients present with weakness in muscles innervated by the cranial nerves. In more severe cases the paralysis gradually progresses in a descending order and may affect respiratory muscles leading to mechanical ventilation. Routine laboratory tests or radiology are unhelpful in initial diagnostics. A practicing physician should administrate botulinum antitoxin immediately when food-borne botulism is suspected since it may be life-saving.