More and more data indicate that SARS-CoV-2 infection causes neurocognitive deficits in a significant proportion of patients. The structure, mechanisms, and course of these disorders are currently unknown. The aim was to study phenomenological characteristics of cognitive impairment in patients with COVID-19. Patients and methods: a total of 2500 hospitalized patients with COVID-19 were examined by a psychiatrist. Clinical examination revealed cognitive decline of various origins in 540 (21.6%) patients, including disorders due to previous cerebrovascular accidents. Patients and their relatives didn’t observed cognitive impairments in patients before COVID-19 infection in 51 (2.4%) cases. These symptoms appeared only against the background of coronavirus infection. These patients were examined clinically and using MMSE in connection with complaints of “decreased memory”, “fog in the head”, “attention deficit”. In 37 (1.48%) patients, a decrease in MMSE score was not found, despite a clinically detectable slowing of mental activity, worsening of active attention, and signs of exhaustion. Decreased scores of the MMSE were found in 14 (0.56%) patients, among them 5 men and 9 women aged 62.57 ± 14.69 years, 95% confidence interval 54.08–71.05. These patients were included in the analysis. Results: the severity of cognitive impairment in patients with coronavirus infection varied over a wide range, and there was no parallelism between the severity of cognitive deficit and the severity of COVID-19. On the MMSE scale, at the first examination, an indicator corresponding to the gradation of the scale “mild dementia” was detected in 3, “moderate” — in 9, and “severe dementia” — in 2 patients. The structure of the neurocognitive syndrome was dominated by speech and attention disorders. All patients with cognitive impairment were characterized by the presence of concomitant somatic diseases. Conclusion: it is possible to identify the neurocognitive syndrome associated with COVID-19 when the following conditions are met: 1) occurrence against the background of coronavirus infection, 2) the absence of neurocognitive disorders before the viral infection, 3) the absence of symptoms of confusion, 4) the absence of parallelism between the severity of the physical state and the MMSE score.