“How long does it take to recover from flat foot surgery?”

Three months I would imagine putting foot in a cast to immobilize.

Hello. This is really not my specialty and really depends on what procedure is planning to be performed. It is best to discuss this with the surgeon. However some general comments for you. This is big surgery and not always successful. You should have exhausted all non-operative options (orthotics, exercise, shoe type etc) before any surgery. If the pain is so bad with just walking then surgery is reasonable. For most bone procedures you are probably looking at 3 months or more before simple walking is comfortable and I have had patients that it has been close to a year before they were happy and would do it again. Personally I would get several opinions prior to any major for surgery. Good luck.