Objectives: To examine the factors associated with the investment of hospitals in five different types of mental health services and explore mechanisms of mental health resources growth in Taiwan. Method: A cross-sectional study was conducted, and mailed questionnaires were used to collected data from the managers of all (136) hospitals. Logistic regressions were employed to examine whether institutional linkages, socio-economic levels, and the mental health resources capacity surrounding hospitals, and the profit consideration were associated with the future investment of hospitals in mental health services. Results: 82 of 136 hospitals responded to the questionnaires, resulting in a response rate of 60.3%. The respondents were not different from the non-respondents across the variables examined. Institutional linkages are significantly statistically associated with future investment in different mental health services. Various variables were differently associated with the future investment of hospitals in different types of mental health service. Being a teaching hospital or a hospitals that has more than 20% of inpatients transferred from other hospitals were significant factors associated with investment in acute psychiatric inpatient service. Conclusions: Different variables are associated with different types of mental health services. The results indicate that more work should be done to look into the different mechanisms for the growth of mental health services.