Do you have the right to refuse a blood test on a DUI stop? Yes, and I would always refuse the blood test if I knew it was going to hurt me. In other words, I've had some to drink and I don't know what my blood alcohol level is. I'm not going to want to just give that over to the police without them going through the extra hoop of getting a warrant. There are hundreds of sober drivers getting DUIs now, and I teach those sober drivers, when you get suspected of a DUI, absolutely take this blood test or the breath test.