This thesis is based on a study on health and work environment among the Royal Norwegian Navy personnel. Background: The health among navy personnel is of concern both for the sake of the personnel themselves and from the perspective that healthy navy personnel are necessary for a well functioning navy defending our country. As there had been general concerns about risk factors for the Navy employees’ health, the Chief of the Naval Staff decided in January 2001 to establish the project Health, Safety and Environment in the Navy. The goal of the project was to give a basis for further action regarding the Health, Safety and Environment work within the Navy. As one part of this project, a questionnaire survey of the general work environment and the health of the employees was carried out by the University of Bergen. This thesis is built upon data from the survey and includes four studies. Aims of the studies: The aim of study I was to compare the health status among naval officers with that of the general population of Norway. The study also investigated the association between health-related quality of life and military officers’ rank. The aims of study II were to determine the prevalence of self-reported musculoskeletal disorders (MSD) among military personnel and civilians in the Navy; and to assess the association between physical activity at work and at leisure and MSD. The aim of study III was to study the relationship between experiencing and coping with life-threatening events and self-perceived health. The aim of study IV was to study whether psychosocial factors at work were associated with bullying when observed by individuals, or observed by groups of individuals in different departments, or both. The aim was also to see whether these associations changed when data from the bullied were excluded. Material and methods: The data were collected in a cross-sectional study by using a questionnaire. In all, 3878 Navy employees were eligible for the study. In study I, we studied 1316 male military officers from 25 to 62 years of age. We studied their health status by using the SF-36 Health Survey (SF-36) scores standardized for sex and years of age. The data from our study population were compared with data acquired from the Norwegian Social Science Data Service of the general Norwegian population. In the comparison, adjustments for being at work and educational level were made. To study the association between military rank and health status the mean raw scores for the eight SF-36 subscales were used. In study II, data from questions about MSD, physical activity and background demographics from the 2265 military and civilian workers 18 to 70 years old were used. The prevalence of MSD in nine body parts was compared between the military and civilian workers. In study III, the 2265 military and navy employees with different types of work on ships and ashore participated. We studied the relationship between the number of lifethreatening events, occupational status, sex, age, and the extent of putting these events behind. The SF-36 was used as a measure of self-perceived health. The possible trends between the degree of putting the life-threatening events behind oneself and each of the eight SF-36 scales were calculated. In study IV, 1657 military personnel were studied both as individuals and as groups at 97 departments. Self-experienced and observed bullying as well as scores for psychosocial scales using the General Nordic Questionnaire for Psychological and Social Factors at Work; QPSNordic were calculated both for the individuals and as a mean for each Navy department. The associations between the psychosocial scales and the occurrence of bullying at the individual and department level were studied. The analyses were repeated excluding those being bullied. Results: In study I, we found that the naval officers in the Navy have a similar health status to the working population in Norway with similar educational level. Military rank was not independently associated with the health status among the naval officers. In study II, we found that the civilian personnel had a higher prevalence of MSD than military personnel in nine body parts, but only in the neck and lower back when adjusted for years of age, sex, physical activity, body mass index, smoking, education and physical stressors. Higher physical activity was associated with less reported MSD for six body parts; the neck, shoulders, hands, upper back, lower back and hips. In study III, we found that the military personnel seemed more likely to have put the life-threatening events behind than the civilians. The extent of putting the events behind oneself was clearly correlated to self-perceived health as measured by the SF- 36 scales bodily pain, general health, vitality, social functioning, role-emotional and mental health, and these associations had linear appearances. The personnel who had “not at all” put the events behind had clearly lower outcomes on these scales compared to those who had not experienced life-threatening events. In study IV, we found that the psychosocial work environment as measured by the group and organizational QPSNordic scales fair leadership, innovative climate and inequality were associated with high occurrence of bullying at the individual and at the department level; meaning that unequal treatment and lack of fair leadership and innovative climate were associated with high occurrence of bullying. Repeating the analyses excluding those being bullied changed the estimates minimally. Conclusion The population of male military officers had a similar health-related quality of life as the Norwegian population with the same educational level. In addition, this personnel group had a lower prevalence of MSD compared to the civilian personnel. However, this does not preclude that groups of military personnel have health problems. We found that those who had not been able to put the life-threatening events behind had an associated poorer self-perceived health as measured by the SF-36 compared to those that had no such events. In addition, we found a group of military personnel that were bullied, which affects health negatively, and others that observed bullying, which may have negative effects on health. For the occurrence of bullying the work environment seemed to play an important role. More physical activity was associated with lower prevalence of MSD for both military and civilian personnel. Although the civilian personnel had put the life-threatening events behind to a smaller extent than the military, those who had put the events behind had better self-perceived health than those who had not put them behind.