Background: At one time, it was expected that if an individual reached young adulthood without smoking, his/her risk for initiation was minimal. However, recent data suggest that smoking initiation among young adults may be increasing. One particularly vulnerable population of young adults for smoking initiation is military recruits. This study examined whether a modified version of the Pierce Susceptibility Questionnaire (PSQ) might be useful for identifying military recruits who are vulnerable for the initiation of tobacco use. Methods: Active duty recruits entering the U.S. Air Force over a 1-year period (n=31,107) were assessed upon entry into basic military training (BMT), and a subsample was also assessed at 12 months following training. Results: The modified PSQ predicted initiation of cigarette use for all categories of baseline smokers (never, experimenters, former smokers, and regular users). The likelihood of initiating smoking after BMT was substantially higher among those identified as susceptible than among those identified as not susceptible. Conclusions: It is likely that the PSQ would prove to be a valuable tool in attempts to reduce tobacco use in the military. The predictive abilities of the measure could be used to target intervention and prevention efforts towards those most at risk.