The International Committee of the Red Cross investigated an outbreak of beri-beri in a prison in West Africa. Twenty-five prisoners out of a total of 1020 died over a period of 11 weeks--exceeding the crude mortality rate of 1/10,000/day, a threshold for serious concern. Two hundred and eleven prisoners had clinical signs of beri-beri. An immediate response to treatment with thiamine was seen and no further deaths occurred. The triad of a positive squatting test, oedema and a diet consisting exclusively of white rice should lead to the diagnosis of beri-beri. The disease is more common than generally assumed, also in Africa and especially in prisons.