If you have international call roaming then YES it will WORK!!

if you are planing to use it with local carrier then read below,


SPRINT(also VERIZON) uses CDMA technology...so my answer is NO!! ( I worked with Sprint for sometime back)

But can you make it work?
Theoretically answer is YES....(Very TOUGH, only Experienced TECHNICIAN can do it)!!

(Wipe the Software and adjust it with the provider's code at your country CDMA only)

Is it easy?
NO

I also know GRAY MARKET TECHNICIAN  in INDIA, can convert CDMA into GSM phone!! ( i have no clue how do you do that)

ALSO for ATT make sure its UNLOCKED and QUAD BAND ( but you can easily unlock GSM PHONES)

CDMA= NO SIM CARD
GSM=SIM CARD NEEDED