RoamTheWorldCellPhones.com

Cellphone GSM Frequencies: 850/1900

(This means you will need a GSM cellphone that will work on 850MHz or 1900Mhz to use it in Puerto Rico.)

Cellular carriers for Puerto Rico

AT&T Mobility (Puerto Rico) (AT&T Mobility – Puerto Rico)

Frequency: GSM 850/1900
Website: www.att.com

Coverage Map (NONE)

Puerto Rico Telephone Company Inc. (Claro GSM)

Frequency: GSM 850/1900
Website: www.claropr.com

Coverage Map (NONE)

If you've used either of these networks or roamed in Puerto Rico, please post about your experience and the cost. Feel free to ask questions.