This study aimed to investigate the effectiveness of managerial decisions of middle-level managers in the projects of maritime industry in Indonesia, due to dysfunctional behavior and budget pressures that are not proportional on Indonesian seaport limited companies as an important part of the maritime economic activities emerging in the reform era in Indonesia. This research was conducted on the managerial level whose respondents have a role as decision makers, and implementers of budget in each work unit activities of seaport companies. The results showed that budgetary pressure and resistance have negative and significant effect on the managerial decision, while the dysfunctional behavior manifested by selfconfidence is less likely able to affect the managerial decisions. The results of this research can be used as a basis in decision-making process, especially in seaport companies responsible for conducting Indonesian maritime industry projects.