On 3 April 1994, the Western Sector Public Health Unit was notified of an outbreak of gastroenteritis at a Christian youth camp. Attending the camp were 820 people; 241 (42 per cent) of 574 camp participants who completed a questionnaire reported illness. Of these, 230 met the case definition. Main symptoms reported were stomach cramps (78 per cent), diarrhoea (67 per cent) and nausea (46 per cent). Bacterial analysis of leftover chicken grew 2.3 x 10(7) and 3.3 x 10(7) colonies/g of Clostridium perfringens, and we identified Type A enterotoxin of C. perfringens in four of seven stool samples collected from ill people. Camp participants who consumed chicken at lunch on the second day of the camp were nearly four times as likely to be ill than those who did not (relative risk 3.81, 95 per cent confidence interval 3.07 to 4.72). There were deficiencies in hygiene and food preparation. We highlight the importance of time and temperature controls in food preparation and storage to prevent contamination and subsequent poisoning by C. perfringens or other food pathogens. This investigation demonstrates the importance of a multidisciplinary team when investigating disease outbreaks.