Greece is a Member-State of the European Union and has signed the Schengen Agreement. While traveling within the E.U., you only need your Identity card. However, a passport is necessary for a number of other transactions, such as currency exchange, purchases, etc.
Visas are not required by European citizens from countries that are part of the Schengen Area. Greece as a member of the Schengen Agreement, has abolished controls on common internal lands, at air and sea borders and allows Member-State citizens to travel around without a visa for a short stay period of up to three (3) months. However, keep in mind that airlines and other carriers require a valid passport and/or identity card.
Citizens coming from countries that have not yet joined Schengen Area may require a visa to enter Greece. The E.U. visitors from these countries can acquire further information from the Hellenic Embassies or Consulates in their countries, or from their travel agencies. Before visiting Greece, please consult the detailed information on the Ministry of Foreign Affairs' website and find out whether you require a Visa.
Note: During your stay in Greece, if you require a Visa, you are advised to have suitable insurance coverage for emergency medical or other needs.