Yes, you can use your T-Mobile phone in Aruba. Just be sure you have a world phone, which is most of the newer phones. Call T-Mobile and they will program your phone for you while you are on the phone. I used my phone in Aruba last December. It was $1.49 per minute and the quality was the same as if I used it in the states. T-Mobile came into existance when the German phone company bought out Voice Stream. They already became a worldwide cellular company. Have Fun with it.