This thesis focused on mental health stigma in the Dutch military by examining two important decisions that military personnel with mental health issues and illnesses (MHI) face. First, the decision of whether or not to seek treatment for MHI was examined, and the extent to which stigma plays a role in this decision. Second, the decision of whether or not to disclose MHI to a supervisor, and the extent to which stigma plays a role in this decision, was examined. Both these decisions can potentially impact the sustainable employment and well-being of military personnel with MHI. Qualitative as well as quantitative research methods were used to examine these decisions. The findings of this thesis showed that mental health stigma exists in the Dutch military, and that it forms a barrier to both treatment seeking and disclosure of MHI to a supervisor. Additionally, the findings highlighted the importance of positive disclosure experiences for the sustainable employment and well-being at work of military personnel with MHI. To improve sustainable employment and well-being at work of military personnel with MHI, it is important that seeking treatment and disclosing MHI are facilitated in a safe environment. This can be done by targeting mental health stigma. Further implications for practice and policy are discussed in this thesis, together with suggestions for future research.