Pattinson has been bothered for some time by a problem with his lower abdomen which is not related to cricket.
Cricket Australia Chief Medical Officer Professor Justin Paoloni said: "The recovery times will be determined once the surgery is completed but James is expected to return to training in approximately four weeks. His preparation for the Ashes is not expected to be affected but his availability for the ICC Champions Trophy will be determined at a later stage."
The complaint started to bother Pattinson during Australia's recent tour of India where his side lost the Test series 4-0.
Pattinson was one of 20 players offered a central contract by Cricket Australia on Wednesday, indicating he will be part of the Ashes party heading for England in the summer.
Paoloni added: "James Pattinson will be having surgery tomorrow for a non-cricket related medical condition in his lower abdominal region that has been troubling him during the latter part of the recently concluded VB Tour of India.
"James has undergone tests and consulted specialists since returning from India, and it was felt that surgery is absolutely necessary at this time."
- Sports & Recreation
- James Pattinson