This paper describes the investigation of a disease outbreak among 10 adult pigs in Nsukka, Anambra State, Nigeria. Prior to the investigation one sow died of the disease. Trypanosomes were later detected in the blood of two of the nine pigs subsequently investigated. All the pigs were then treated with deep intramuscular injection of 8 mg/kg diminazene aceturate (Berenil). Thirty six days after treatment a boar and a sow relapsed with signs similar to the ones shown previously. Further examination of their blood and faeces revealed nothing of parasitological significance. Following deteriorating condition and development of nervous signs the boar was salvaged while the sow died of the infection. Brain impression smears taken from both animals during postmortem examination revealed numerous trypanosome parasites identified by morphology and blood incubation infectivity test (BIIT) as Trypanosoma brucei brucei. The clinical and economic significance of the outbreak are discussed.