The role of stress on soldiers¿ efficiency and well-being has been largely acknowledged in Military psychology. Most research on stress within the military, however, has focused personality characteristics, and in particular on emotional instability as the crucial antecedents of soldiers' resistance to stress. Consequently, many of contemporaneous attempt to reduce stress on the military have emphasized the need for an accurate recruiting, under the basic premise that emotional instability is a stable trait resistant to change. An unanswered question remains, however, regarding the potential mechanisms linking emotional instability to the development of symptom of work related stress in the military. This research project aims to contribute to this line of research, by pointing to the role of Work Self-efficacy beliefs in managing Negative Emotions (WSNE) as the mediator of the relation between emotional stability and stress resistance. To do so, we will use a sample of military cadets of Italian Financial Police (i.e., Guardia di Finanza or gdf). This organization represents a perfect scenario to investigate the relationship between personality factors and WSNE on the development of stress related symptoms. Indeed, cadets are at their first military experience, must manage possible dangerous tasks (i.e., the use of weapons), adapt to a highly competitive organizational environment characterized by strict conduct rules and forced discipline. For testing our hypotheses we will collect data on personality, WSNE, and on subjective and objective data on stress on a cohort of military cadets three times from their entrance in academy at the end of every year, until their third (and last) year in four prestigious military academies of the gdf. Our results will offer new insight to research on stress prevention in the military by pointing to the role of malleable psychological structures (such as WSNE) in improving soldiers¿ ability of dealing with work related stress.