Can you wear a hat after a hair transplant procedure is finished so that nobody knows about it?
The good news is, yes - you can wear a loose fitting hat immediately after your hair transplant procedure, even before you step outside of the clinic. Be sure that you put it on and take it off carefully and gently as to not rub against the newly transplanted hair. Ten days after your hair replacement surgery, the follicular unit grafts will be secure in your scalp and you can go back to wearing a hat normally with much less caution.
In my opinion however, give your scalp as much of a chance to breathe as possible, minimizing the use of the hat when inside of your house or in places away from public eye. Though a hat will not stunt hair growth, exposing your scalp to the air will facilitate healing.