Empirical evidence has demonstrated that an individual’s cultural values can influence his or her mental health. This study extends previous research by proposing and testing a model that examines mediating processes underlying the relationship between individuals’ cultural values and their mental health. This 2-stage study used data collected from 208 (at time 1) and 159 (at time 2) full-time staff employed by private enterprises in Taiwan. The author tested hypotheses through the use of hierarchical multiple regression. The results showed that under horizontal individualism and vertical collectivism, the predictors of negative mental health (ie, somatic symptoms, anxiety and insomnia, social dysfunction and/or severe depression) were partially and almost completely achieved through the mediating effect of the negative attitudes toward emotional expression.