Even though IT use has numerous benefits for users and organizations, such as improved performance and greater productivity, an increasing number of users experience IT use as a source of stress, i.e. technostress. Since such technostress can result in decreased user well-being, it is important to understand what leads individuals to perceive it. Based on psychology research suggesting user personality as a cause of stress perceptions, this research uses the Theory of Personality to investigate how user personality influences technostress. In developing our research model, we focus on the dynamic, context-specific trait IT mindfulness and on the degree to which this trait determines the perception of technostress. This study contributes to technostress research by revealing that user personality in general and IT mindfulness in particular are determinants of technostress, which organizations should account for to prevent employees from perceiving technostress.