Visa Regulation for Portugal varies for the citizens of different countries. Therefore, for citizens of U.S., there is no need for Visa, if the visitor is staying for less than 90 days on the country. However, the passport shall be valid for 6 months prior to the date the visitor plans to stay. The same regulation is applicable to all citizens of Australia, Swiss, EU, EEA or any other party of the Schengen Agreement. Additionally, here are the countries that do not need the visa to enter the Portugal: Andorra, Antigua and Bermuda, Argentina, Bahamas, Barbados, Bolivia, Bosnia, Brunei, Canada, Chile, Costa Rica, El Salvador, Guatemala, Honduras, Hong Kong, Israel, Japan, Korea, Macao, Malaysia, Mauritius, Mexico, Monaco, Montenegro, Nicaragua, New Zealand, Panama, Paraguay, Saint Kitts and Nevis, San Marino, Serbia, Seychelles, Singapur, Taiwán, Uruguay and Venezuela. However, if the visitor is the citizen of another country it is recommended to visit the Embassy of Portugal in a home country.