RoamTheWorldCellPhones.com

Cellphone GSM Frequencies: 900/1800

(This means you will need a GSM cellphone that will work on 900MHz or 1800Mhz to use it in Monaco.)

Cellular carriers for Monaco

French mobile operators also work in Monaco.

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