This paper reports an independent epidemiological study to evaluate the validity of the results of an official investigation into an outbreak of gastroenteritis at a university campus in Yasuj, central-south Islamic Republic of Iran. The official report of the outbreak by the Department for Disease Control at the provincial health centre found only 65 cases over a 5-day period, all females, living in the student halls of residence. This contrasts with a questionnaire survey of 963 students at the same university, which found 395 students (192 males and 203 females), living in residences and at home, who reported at least 1 gastrointestinal symptom over a 12-week period. Within this period at least 2 outbreaks occurred. Such a large discrepancy between the official report and the current study suggests that the health services and the public may have been misled about the proper response to the outbreak.