Greece follows the Schengen Agreement and provisions for short-term visits. Citizens of all countries applying the Schengen acquit in full, plus associated countries enter with any valid I.D. card and are not subjected to border controls.
Holders of regular passports from the rest of the world need a visa in order to enter Greece (and the Schengen Area).
For more information on how to obtain a visa, you may visit the following site: http://www.visitgreece.gr/en/before_you_travel/passports_and_visas
You may need a visa to enter Schengen
Under the Schengen regulations, citizens of countries listed below need a valid visa to visit or transit any country in the Schengen area:
Afghanistan, Algeria, Angola, Antigua and Barbuda, Armenia, Azerbaijan, Bahrain, Bangladesh, Belarus, Belize, Benin, Bhutan, Bolivia, Botswana, Burkina Faso, Burundi, Cambodia, Cameroon, Cape Verde, Central African Republic, Chad, China, Colombia, Comoros, Congo, Cuba, Djibouti, Dominica, Dominican Republic, Ecuador, Egypt, Equatorial, Guinea, Eritrea, Ethiopia, Fiji, Gabon, Gambia, Georgia, Ghana, Grenada, Guinea, Guinea-Bissau, Guyana, Haiti, India, Indonesia, Iran, Iraq, Ivory Coast, Jamaica, Jordan, Kazakhstan, Kenya, Kiribati, Korea, Kuwait, Kyrgyzstan, Laos, Lebanon, Lesotho, Liberia, Libya, Madagascar, Malawi, Maldives, Mali, Marshall Islands, Mauritania, Micronesia, Moldova, Mongolia, Morocco, Mozambique, Myanmar, Namibia, Nauru, Nepal, Niger, Nigeria, Northern Marianas, Oman, Pakistan, Palau, Papua, New Guinea, Peru, Philippines, Qatar, Russia, Rwanda, Saint Helena and dependencies, Saint Lucia, Saint Vincent and the Grenadines, Samoa, São Tomé and Principe, Saudi Arabia, Senegal, Sierra Leone, Solomon Islands, Somalia, South Africa, Sri Lanka, Sudan, Suriname, Swaziland, Syria, Taiwan, Tajikistan, Tanzania, Thailand, Timor-Leste, Togo, Tonga, Trinidad and Tobago, Tunisia, Turkey, Turkmenistan, Tuvalu, Uganda, Ukraine, United Arab Emirates, Uzbekistan, Vanuatu, Vietnam, Yemen, Zambia, Zimbabwe.
Nationals of certain other countries must have travel insurance, but do not need a short-stay visa. These include Brazil or Argentina, for example.
Those requirements might change. To be certain, the best sources of information will be your embassy, consulate. For more information you may visit the site: http://www.axa-schengen.com/en/schengen-visa-countries
Your passport must be valid for at least six months after your return.