Ports are considered critical infrastructure as they play an important role in international trade and overall economic growth. There are around 4,000 ports worldwide, of which around 1,200 are located in Europe alone. Ports around the world face the same challenge of providing competitive services while ensuring that the negative impact on the environment is minimized, with the environmental problem being particularly acute in peri-urban ports. While the majority of maritime transport emissions are generated during shipping, ships' auxiliary engines run during port calls to keep the ship's systems running. Ships in port usually contribute more than half of all port-related emissions. The remaining emissions come from the port itself. The aim is to reduce port emissions by 90% by 2050. Ports are already working hard to reduce their environmental footprint and gain the support of local communities. They are applying a combination of soft and hard measures, such as reduced charges for greener ships or a truck arrival booking system and other digitalization approaches, as well as offering alternative fuels for ships and shore power (cold ironing), purchasing sustainable cargo handling and other terminal equipment, using renewable energy sources, developing electrical micro grids, etc. These measures represent a major financial, infrastructural and operational challenge, at least initially. This paper presents measures (examples of best practices) that ports have implemented to achieve cleaner operations with an indication of the cost of implementation.