Harmonizing economic activities with environmental considerations has emerged as a new globalizing phenomenon for ports. The phenomenon is labelled as ‘green port’. There is however no canonical way of turning green port into business reality. Some advanced ports have adapted it and African ports are also beginning to follow. The Freeport of Monrovia in West and Central Africa had its process of incorporating environmental considerations into its operational practices in an environmental reform labelled as ‘going green’, akin to the green port phenomenon. The process interrupted routinized port activities and behavior. Employees of Freeport of Monrovia and stakeholders could not foresee the meaning and consequences of such reform. The uncertainty triggered a process for employees and stakeholders to collectively make sense of and react to their new situation. This paper integrates Weick's sense-making properties with Weber and Glynn's institutional mechanisms affiliated to sense-making as a conceptual tool to analyze and understand the process by which meaning was assigned to Freeport of Monrovia's environmental reform and also how it became institutionalized. The analysis is based on hands-on empirical research on an environmental capacity strengthening project executed in 2013 in the Freeport of Monrovia as part of its institutional reform from a service port into landlord port. Findings bring to light the dynamic interplay of institutions and sense-making in the greening of Freeport of Monrovia.