BACKGROUND Recent studies have shown a substantial decline in caries experience in Australian Army recruits between 1996 and 2002-2003, and in Australian adults between 1987-1988 and 2004-2006. However, studies in children have reported an increasing trend in caries experience between 1998 and 2002. The aim of this study was to investigate caries experience in Australian Army recruits in 2008. METHODS A cross-sectional study involving 1084 Australian Army recruits was conducted from January to May 2008. Data were obtained from a clinical dental examination with bitewing radiographs, and a questionnaire elicited socio-demographic data and history on lifetime exposure to fluoridated drinking water. RESULTS Mean DMFT scores were 3.16, 4.08, 5.16 and 7.11 for recruits aged 17-20, 21-25, 26-30 and 31-35 years, respectively. Recruits with a lifetime exposure to fluoridated drinking water had a mean DMFT of 3.02, while recruits with no exposure had a mean DMFT of 3.87. CONCLUSIONS Caries experience in Australian Army recruits aged 17-25 years increased between 2002-2003 and 2008. Recruits with lifetime exposure to fluoridated drinking water had 25 per cent less caries experience compared with recruits who had no exposure to fluoridated drinking water after adjusting for the effects of age, gender, education and socio-economic status.