Timing is SUPER IMPORTANT when baking boneless and skinless chicken breast. Chicken breast is a lean protein and tends to dry if baked for too long or at the wrong temperature. Baking times vary depending on the size and thickness of the chicken. A medium size chicken breast (5 to 6 oz, takes approximately 20 to 25 minutes to bake in a 400 degree oven. Check closely at the end with anu003ca href=u0022https://rstyle.me/+SljGTcfg-N2bOPJVCkKyUgu0022 target=u0022_blanku0022 rel=u0022noreferrer noopeneru0022u003e instant thermometer.u003c/au003e I always bake chicken breasts at 400 degrees Fahrenheit as the high temperature helps seal in the juices (and the flavor).