The aim of the present study was to investigate the effect of different coping styles on the development of self-reported mental health problems in a radically changing context. This was investigated, using a longitudinal design, by following soldiers from before entering service to 8 months of service. Based on their scores on the 30-item General Coping Questionnaire, soldiers were allocated to one of three groups: those whose coping styles were emotional, avoidance, or task focused. These three groups were assessed four times. The General Health Questionnaire (30-item version), Ursin's Health Inventory, and the Alcohol Use Disorders Identification Test (AUDIT) were used as dependent measures. Avoidance-focused soldiers reported an increase in General Health Questionnaire scores over time. Furthermore, the avoidance-focused copers revealed higher scores on the AUDIT questionnaire as well as an increase in AUDIT scores over time. The present study showed that there was an interaction of personality variables and contextual factors involved. More specifically, young subjects with a preference for an avoidance-focused coping strategy are at greater risk of experiencing symptoms of mental health problems compared with task-focused and emotion-focused subjects when exposed to a radically changing environment.