United States citizens need only to show a valid, up-to-date, government-issued ID, such as a driver's license, when flying into Puerto Rico or passing through security checkpoints located throughout the island. Citizens from other countries will require a valid passport to enter, and visa requirements for Puerto Rico are the same as for the U.S.
Visitors from the U.S. and Canada do not require any special vaccinations before visiting Puerto Rico. It is advisable to consult with a physician regarding your planned activities while in Puerto Rico to determine whether you might be at risk for diseases such as hepatitis, typhoid or tetanus. In general, the risk of tourists contracting these diseases during their stay is considered to be very low.
U.S. citizens are not required to go through customs upon either entering or leaving Puerto Rico. Citizens from other countries, however, must clear customs. Items intended for personal use, including small amounts of tobacco and alcohol, may be brought into the country.