OBJECTIVE: The present study sought to determine whether job insecurity is associated with personality traits and beliefs. In addition, it was tested whether aspects of personality confounded the relationships between job insecurity and health, or moderated this association. METHODS: At the first data collection, 5163 persons participated, and at the second data collection, 1946 persons of a random sample participated. Data were obtained from Oslo Health Study. RESULTS: The job insecurity aspect concerning confidence in having a good job in 2 years was more strongly related to the health variables, and particularly with mental distress, compared with other aspects of job insecurity. Type-A behavior predicted an increase in upper back pain (beta 0.07), while optimism predicted a change in lower back pain (beta -0.07). CONCLUSIONS: Job insecurity is associated with health; this association is strongest for mental distress and self-reported health, and weaker for back-pain.