Puerto Vallarta is very safe! Though you should use the same caution and awareness as you would when traveling anywhere in the United States or abroad. Don't attract unnecessary attention by wearing anything overly flashy (everyday jewelry is fine), or being outwardly under the influence in public. As with anywhere, remain aware of your surroundings, especially at crowded or toursity areas such as along the beach/boardwalk, taking care with purses and wallets.

You can never drink the tap water in Mexico! Not even the locals do. Bottled or filtered water is available everywhere, and since it is such a popular destination you are safe to drink the water and ice served at restaurants and bars, cafes (unless you go super off the beaten path!).

As a tourist, you may be better off taking the precaution of using bottled water to brush your teeth, and do try to remember to keep your mouth shut when you shower. That said many locals and travelers brush their teeth with tap water, but they'll rinse and spit, careful not to swallow.