Introduction: Internal Carotid Stump Syndrome may be one of the possible causes of ischemic stroke (iCMP), as well as retinal infarction (RI). Syndrome of the occluded internal carotid (ACI) (stump syndrome) is a nosological unit, which is characterized by an onset of ipsilateral iCMP or RI of thromboembolic ethiology in patients with occlusion of ACI via the externa carotid or arteria ophthalmica. In my thesis, I have concentrated upon the specification of the stump syndrome, its diagnostics and treatment; furthermore I have assessed the appropriateness of surgical approach in comparison with conservative approach. Material and methods: A total of 621 patients with occlusion were treated in two centres in the course of five years. In a group of 40 patients, the ACI occlusion was detected sonographically, the length of the occluded ACI being >5 mm, with normal vasoreactivity based upon SPECT CO2 and excluded cardiogenic cause of iCMP. The patients were divided in two groups - surgical and conservative. Patients were monitored in 6-month intervals for the total period of four years. Results: No RI or iCMP were detected in the surgical group; one patient died six months after surgery. We observed one case of amaurosis fugax in the conservative group. Conclusion: Ultrasound examination is a fully sufficient...