The Government of the Cayman Islands is currently considering to expand the marine protected areas around its three islands. To support their decision-making process, Wolfs Company is developing a cost-benefit analysis (CBA). Although increasing the size of the MPAs will lead to higher management costs for the Cayman Islands, it is expected that important ecosystem services provided by the marine environment will yield higher benefits in the future. In this CBA, costs and benefits in different MPA scenarios are compared. In the light of this assessment, the value of relevant ecosystem services for local residents and the tourism industry have been assessed.