The metropolitan areas must comply with several duties, particularly:

a) To participate in the production of public investment plans and programmes;

b) To plan the conduct of public entities of metropolitan scope and to organize supramunicipal investments;

c) To participate in the management of regional development programmes, particularly within the scope of the Community Support Frameworks;

d) To contribute to the definition of metropolitan services and equipment networks;

e) To participate in public entities of metropolitan scope in the field of transports, water, energy and solid waste processing;

f) To ensure the cooperation between the municipalities and the central administration services in the areas of public supply systems, sanitation infrastructures, wastewater and urban waste treatment; health facilities network; educational and vocational training network; regional planning, preservation of nature and natural resources; safety and civil protection; mobility and transports; public facilities network; cultural, sports and leisure facilities network.

The metropolitan areas must comply with the duties transferred to them by the central administration, as well as with the competence delegated by the municipalities they comprise.

It is the competence of metropolitan areas to appoint their municipal representatives to public entities or businesses of a metropolitan nature.