A 1 yr 8 mo–old, previously healthy, primiparous female babirusa (Babyrousa celebensis) presented acutely recumbent and minimally responsive approximately 36 hr after giving birth to a single piglet. Toxic mastitis was diagnosed based on physical examination and laboratory results. The mammary tissue was firm, discolored, and produced negligible amounts of milk. All of the teats were eventually affected, resulting in the inability to provide adequate nutrition to the piglet. Although toxic mastitis has a poor prognosis in domestic sows, this babirusa recovered completely with aggressive management, including antibiotics and supportive care.