Thrombosis, especially in pregnancy, is due to a prothrombotic state and involves the venous system. Localization in an arterial segment is rare. Floating carotid arterial thrombosis is a very rare occurrence, but it is very devastating. The authors report the case of a pregnant patient in whom are associated a thrombotic predisposition and a traumatic event of the neck which resulted in a limited dissection and a floating thrombosis of the common carotid artery. The onset was characterized by sudden neurological deficits, including numbness of the right-hand fingers and right limb weakness, which regressed after admission. The patient underwent a surgical operation with success. Her pregnancy continued, and an ultrasound scan 12 months later confirmed the patency of the prosthesis, in the absence of neurological symptoms. Hormonal changes may reveal the condition of thrombophilia, which, however, occurs more frequently in the venous system and is a condition related to the free-floating thrombus. No guidelines exist for medical or surgical management. The endovascular approach appears to present a greater risk of embolization as an alternative to open surgery. This case demonstrates that the prothrombotic state and the presence of neurological symptoms are suggestive of arterial thrombosis in pregnancy and that the multidisciplinary approach is mandatory to achieve good results.