This article aims to investigate the possible impact of carotid stenosis, i.e., the atherosclerotic narrowing of the inner surface of the carotid artery, on language performance. The majority of patients with carotid stenosis are considered asymptomatic, as they have not experienced retinal or focal cerebral dysfunction. Here we challenge the traditional assumption that such patients are asymptomatic with regard to neurocognitive functions by demonstrating that chronic cerebral hypoperfusion may have a significant impact on language performance. Twenty-four patients with 50–99% asymptomatic carotid stenosis and 24 healthy controls participated in this study. Language performance was tested with an elicited production task, in which participants had to produce regularly and irregularly inflected Hungarian noun forms. The dependent variable was the amount of errors. Compared to healthy controls, patients with carotid artery stenosis demonstrated lower overall performance on the language production task. Additionally, patients with bilateral stenosis produced more errors than patients with unilateral stenosis. Importantly, patients with the lowest degree (i.e., 50%) of carotid artery narrowing already exhibited considerable language impairment. These results support the accumulating evidence that hypoperfusion secondary to carotid stenosis may be functionally relevant despite the so called ‘asymptomatic’ status of the patients. These findings also highlight the need for including neurocognitive assessment in the evaluation of the clinical status of these patients, and have potential therapeutic implications.