If you're simply wondering how long to bake your Chicken Parmesan at 350°F, the answer is that it depends on the thickness of your chicken breast. If you've pounded out or sliced your chicken breast into thin cutlets, the bake time is only 15-18 minutes. However, for a full chicken breast, the bake time at 350°F will be 25-30 minutes. It's done when the internal temperature in the thickest part of the chicken breast registers 160-165°F or there is no longer any pink inside. (The temp will continue to rise a few degrees after being removed from the oven.)