The aim of this prospective study was to identify key predictors of attrition from Canadian Forces basic training. Baseline health data from 5,169 Canadian Forces recruits (85.4% men) collected using the Recruit Health Questionnaire were linked with administrative data on basic training releases. A total of 8.0% of recruits from this sample was released from basic training. A wide range of factors falling within each of the following categories were examined as potential predictors of attrition: demographic characteristics, social environment, health status, lifestyle, and personality. Logistic regression analyses pointed to increased odds of attrition among noncommissioned member candidates, recruits with one or more dependents, as well as those with an annual household income of less than $20,000, poor/ fair self-rated health, medium/high severity of somatic symptoms, higher neuroticism, lower mastery, and higher agreeableness. Overall, results underscored the importance of good general health and resilient personality to basic training success.