Acute aortic dissection is a relatively common disease involving the aorta. All aortic dissections start with an intimal-medial tear prior to the medial dissection. Several cases of aortic intimal-medial tear without dissection have been reported previously, but only one article presented a photograph of the intimal-medial tear. Herein, we describe 16 patients whose ascending aortas were operatively excised because of what clinically was believed to be acute aortic dissection. Of the 16 patients, 14 had aortic intimal-medial tears without dissection and the other 2 had acute medial dissection of the aorta adjacent to a healed aortic intimal-medial tear without dissection. These aortic intimal-medial tears have been seen in the Marfan syndrome, but none of our 16 patients had the Marfan syndrome. At least 9 of the 16 patients, however, had had aortas similar to those seen in the Marfan syndrome (forme fruste variety). Although the 8 surgeons who operated on these 16 patients described the intimal-medial tears as “aortic dissection”, only 2 had acute dissection adjacent to a healed intimal-medial tear without dissection. In conclusion, although the aortic intimal-medial tear is the initiator of aortic dissection, some patients with intimal-medial tears have no accompanying dissection.