Looking through the literature and other answers, you will find some allow a hat and some don't. I am opposed to allowing my patients to wear a hat after the surgery for multiple reasons. The most important reason is that even if the hat is loose and not directly touching the surgical area, an object or another person could easily bump the hat (especially if it has a brim), and quickly dislocate all the follicles you spent so much money having placed. Also, some patients have forgotten they are even wearing the hat and accidentally move it without thinking. At the 2 week post op mark, you can wear a loose hat. I don't recommend a hat prior to this point. Thanks for the great question.