According to Article 4 of the Greek Citizenship Code:
1. Aliens of Greek ethnic origin, admitted to military academies as officers or non-commissioned officers of the armed services or enlisted in the armed services as volunteers, in accordance with current regulations, lawfully acquire Greek citizenship from the time of their admittance to such institutions or from their enlistment.
2. Aliens of Greek ethnic origin who enlist as volunteers in time of mobilization or war, in accordance with the current regulations, may acquire Greek Citizenship by petition to the Secretary General of the Prefecture without any further formalities.
3. Those receiving promotion to officers, whether in the standing Armed Services or in the reserves, acquire the Greek Citizenship without any further formalities.
4. The military oath taken by the persons mentioned in paragraphs 1, 2, and 3, substitutes for the oath of the Greek citizen.
5. The children of aliens of Greek ethnic origin, who acquire Greek Citizenship in accordance with the previous paragraphs, are entitled to become Greek citizens at the same time their parents acquire Greek citizenship provided they are minors (under the age of 18 ) at the time of their parents’ petition to the Secretary General of the Prefecture.
Have a question?
The preceding text is quoted directly from an English translation of the old Greek Citizenship Code, and there were no amendments announced in the new, 52-page Greek Citizenship Code that took effect May 28, 2010.
I do not know anyone who has acquired citizenship by this method, and I do not represent the Greek military or Greek government, so I cannot interpret its meaning or answer questions.
Go to the Mandatory Military Service in Greece article and retrieve the contact information from there to inquire directly, as each case is uniquely different. The other option is to consult directly with the Greek consulate/embassy if you are outside Greece. Do not consult a forum, listen to rumors from friends/relatives or lawyers advertising themselves on the Internet, or you risk getting misleading information.
*Article last updated January 4, 2012