<p>I think they matter but they are not going to outweigh your SAT score. From what I understand, they mainly use them to make sure that there isn’t any grade inflation going on in your school. If you getting 100’s in AP Chem, but you get a 1 on the AP exam, they suspect grade inflation and not that you were having a bad day. Same goes the other way too. If you have an 80 average in a class but you also get a 5 on the AP exam, it could appear that your school has a very harsh grading system so they will consider that when reviewing your transcript.</p>