The aim of this retrospective analysis was to assess the clinical consequences after intentional left subclavian artery (LSA) occlusion. Thirty-seven patients, 27 type B dissection and 10 thoracic aneurysm, with short proximal neck (less than 2 cm) underwent endovascular treatment with intentional exclusion of LSA origin. No immediate complications occurred. Mean arterial pressure gradient, between right and left arms, ranged from 15 to 45 mmHg. After a mean follow-up of 43.70 + or - 24.01 months, mild left arm symptoms secondary to flow reduction occurred in eight cases (21.6%) but only one required LSA transposition, after 8 months, for visual impairment. Type II endoleaks from excluded LSA occurred in 10 cases (27.0%): in seven patients, leaks were treated with coils and/or glue embolization; in one case, leak sealed spontaneously; one patient died before leak embolization could occur; one patient refused any further treatment. Intentional exclusion of the LSA may be justified when a longer proximal landing zone in the aortic arch is required.