Employees in high-risk occupations can experience stigma associated with developing mental health problems and getting treatment for problems that can oftentimes be attributed to traumatic events encountered at work. The present study examined the perceived unit climate of support for mental health as a predictor of changes (over the course of 3 months) in the perceived stigma associated with seeking treatment, positive and negative attitudes toward treatment seeking, and a preference for handling mental health problem oneself, as well as talking with fellow unit members and a mental health professional about a mental health problem. Active-duty military personnel (N = 349 at Time 1, N = 112 matched at Time 2) completed measures assessing unit climate and individual beliefs about treatment at two points in time separated by 3 months. The results of structural equation modeling revealed strong evidence for perceived unit climate of support for mental health at Time 1 predicting a change in perceived stigma and attitudes toward treatment seeking at Time 2. A more positive perceived unit climate of support was associated with decreases in stigma, more positive attitudes toward treatment seeking, and less negative attitudes toward treatment seeking. Among those soldiers with a mental health problem (N = 164), a more positive perceived unit climate for mental health was associated with a greater likelihood of talking with a fellow unit member about the problem and receiving mental health treatment. Implications of the results for unit-level interventions in high-risk occupations are discussed. (PsycInfo Database Record (c) 2020 APA, all rights reserved).