OBJECTIVE: To report a case of foodborne botulism and subsequent use of the investigational heptavalent botulism antitoxin (H-BAT). CASE SUMMARY: A 60-year-old man was hospitalized with blurred vision, diplopia, and dysarthria. On hospital day 2, the patient was transferred to the intensive care unit for progressive fatigable weakness with ptosis, dysphagia, dysarthria, and nausea. Secondary to worsening respiratory distress, the patient was intubated and placed on a ventilator. The patient could open his eyes only with assistance but still had normal strength in all extremities. H-BAT was administered 48 hours after presentation for possible botulism. The patient then revealed that he consumed home-canned corn several days prior to admission. On hospital day 8, botulinum neurotoxin was confirmed in the patient's serum and the home-canned corn. The patient slowly regained muscle strength and was discharged to a long-term acute care facility on hospital day 22. DISCUSSION: Foodborne botulism is caused by a neurotoxin from Clostridium botulinum and usually occurs after the consumption of improperly prepared home-canned food. Botulism is characterized by symmetrical descending paralysis that may progress to respiratory arrest. The standard confirmatory test for botulism is a mouse bioassay to prove the presence of botulinum neurotoxin. Outside of supportive care, the treatment options for botulism are limited. Individuals with botulism often require intensive care unit monitoring and potentially ventilatory support. H-BAT, the only treatment available for botulism in patients older than 1 year, is a purified and despeciated equine-derived immunoglobulin active against all known botulinum neurotoxins. H-BAT's despeciation significantly reduces the risk of hypersensitivity reactions, anaphylaxis, and serum sickness. CONCLUSIONS: In a confirmed case of foodborne botulism treated with H-BAT, the patient tolerated H-BAT and did not develop any hypersensitivity reactions or serum sickness.