Introduction. Large (1.5―2.5 cm) and giant (>2.5 cm in diameter) aneurysms of the internal carotid artery (ICA) remain one of the complex neurosurgical pathologies in terms of microsurgery. In recent years, endovascular techniques for treatment of paraclinoid aneurysms, in particular ICA reconstruction using flow-diverting stents, have become a priority. However, surgery of flow stents has a number of limitations, therefore the choice of treatment in each case is individual. Purpose. To analyze the results of direct surgery in patients with large and giant aneurysms of the ICA and to determine the role and place of modern microsurgical techniques in the treatment of this vascular disease. Material and methods. The study included 260 patients with large and giant ICA aneurysms who were operated on at the Institute using microsurgical techniques in the period between 2001 and 2015. The mean age of patients was 45.1 years. The male/female ratio was 1:2.5. One hundred sixty four (63.1%) patients were operated on after hemorrhages, of whom 15 (5.7%) patients were operated on in the acute period; 69 (26.5%) patients had a pseudotumoral course of the disease; 9 (3.5%) patients had a mixed course of the disease; aneurysms were incidentally found in 18 (6.9%) patients. The aneurysm localization was as follows: paraclinoid aneurisms in 158 (60.7%) patients, supraclinoid aneurisms in 77 (29.6%) patients, and ICA bifurcation aneurisms in 25 (9.6%) patients. Microsurgical clipping was performed in 228 (87.7%) patients, including 158 (60.7%) patients in whom an intravascular blood aspiration technique was used. Aneurysm trapping using a flowmetry probe was performed in 16 patients, with creating vascular anastomoses in 4 (1.5%) cases. In 16 (6.2%) patients, interventions were completed by gauze strengthening. We performed a comparative analysis of the results of endovascular treatment of paraclinoid aneurysms reported in recent publications and obtained in the present series. Results. Treatment outcomes (Glasgow Outcome Scale) were favorable (Grade 4―5) in 224 (86.2%) patients and satisfactory in 29 (11.1%) patients. Two patients (0.7%) developed diencephalic (electrolyte) disturbances that were successfully corrected using replacement therapy. The mortality was 2.7% (7 patients); the treatment completeness was 94.3%. Comparison with the literature data demonstrated comparable results for both treatment techniques. Conclusion. Microsurgical techniques in treatment of large and giant ICA aneurysms are the methods of choice in complex non-standard cases where endovascular treatment is ineffective or contraindicated. Planning of microsurgical treatment should include the possibility of revascularization surgery. Treatment of these patients should be carried out at large dedicated centers having appropriate expertise and facilities.