A large sample of Finnish military conscripts of the armored brigade were questioned on the extent to which they trusted the information given biopreparedness authorities (such as the police, military, health care, and public health institutions) and how confident they were in the authority's ability to protect the public during a potential infectious disease outbreak, from either natural or deliberate causes. Participants answered a written questionnaire during their initial health inspection in July 2007. From a total of 1,000 conscripts, 953 male conscripts returned the questionnaire. The mean sum scores for confidence in the information given to biopreparedness authorities and the media on natural and bioterrorism-related outbreaks (range = 0-30) were 20.14 (SD = 7.79) and 20.12 (SD = 7.69), respectively. Mean sum scores for the respondents' confidence in the ability of the biopreparedness authorities to protect the public during natural and bioterrorism-related outbreaks (range 0-25) were 16.04 (SD = 5.78) and 16.17 (SD = 5.89). Most respondents indicated that during a natural outbreak, they would have confidence in information provided by a health care institution such as central hospitals and primary health care centers, whereas in the case of bioterrorism, the respondents indicated that they would have confidence in the defense forces and central hospitals.