This paper addresses the estimation of air emissions (CO2, NOX, SOX and PM) released by cruise vessels at port-level. The methodology is based on the “full bottom-up” approach and starts evaluating the fuel consumed by each vessel on the basis of its port-activities individually (maneuvering, berthing and hoteling) and type of propulsion. The input data was based on interviews and surveys to the vessel crew and, on the other hand, real-time data from the AIS system, factor emission from EIAPP engine certificates and vessel characteristics from IHS-Sea web database. The methodology has been implemented to a particular case of 30 cruise vessels visiting the Port of Barcelona and the results are presented both in absolute terms per year (inventory) and through indicators which can be used for estimating emission values in other cruise ports.