Vascular occlusion leading to the development of an ischemic focus or incomplete aneurysm closure is one of the main causes that deteriorate the total results of surgical treatment in patients with cerebral aneurysms. The study covering 50 patients with 54 aneurysms who were evaluated for vascular patency by contact Doppler ultrasonography (CDUS) assessed the role and reliability of this technique. In the study group, the ratio of males to females was 30:24, their mean age was 44 years (23-67 years); the ratio of patients with acute subarachnoidal hemorrhage (SAH) to those without SAH was 24:30. The functional outcomes were assessed by a modified Rankin scale and compared with those in the control group. The clip site was inspected by the results of CDUS in 19 (31.7%) cases; clip reposition was made in 16 (26.7%) cases due to vascular stenosis; an additional clip was use to exclude the aneurysmal functioning part in 1 (1.7%) case. Vascular stenosis was detected in 2 (3.3%) cases; however, the position of clips remained unchanged since aneurysm was excluded under the conditions of its rupture. According to the modified Rankin scale, good results were slightly more in the study group of "acute" patients than in the control group: 96.7% versus 90%; the similar results were obtained in non-SAH patients: 66.7% versus 62.5%; lambda < 1.36). CDUS is a noninvasive, simple, reliable, and inexpensive technique for blood flow evaluation.