Aim: to assess the prevalence of various clinical manifestations in COVID-19 survivors, depending on the time interval after the disease, clinical severity, and the presence of polymorbidity. Patients and Methods: the study included 253 patients (187 females and 66 males), 18–85 years old, who survived COVID-19. The patients were split into two groups based on the disease severity during the acute phase: group 1 consisted of patients with mild COVID-19 illness (n=133); group 2 consisted of patients with moderate and severe COVID-19 illness (n=120). In addition, patients of each of the groups were divided into two subgroups, depending on the time elapsed from the acute phase of COVID-19 illness: in subgroups A the health assessment of patients was performed within 3 months (12 weeks) after the acute phase of the diseases and in subgroups B — 3 months (12 weeks) after the disease, i.e. the time interval ranged from 3 months to one year after COVID-19 illness. A multi-stage phone interview of the patients was used to reveal the presence of symptoms. Also, outpatient medical records of those patients who addressed therapists or narrow specialists, were reviewed. Results: symptoms were revealed both in patients of subgroup 1A (45/52 (86.5%)) and subgroup 2А (42/45 (93.3%)), or, in other words, the symptoms were absent in 7 (13.5%) and 3 (6.7%) patients, respectively. Three months after COVID-19 illness, the symptoms were absent in 34 (42%) patients of subgroup 1B and in 13 (17.3%) patients of subgroup 2B (p<0.001), while at least one symptom persisted in 47/81 (58%) patients of subgroup 1B and 62/75 (82%) patients of subgroup 2B. In both patient groups the most common symptoms comprised fatigue, shortness of breath, and cough. In group 2 patients central nervous and cardiovascular system consequences and arthralgia were frequently reported. The prevalence of comorbidities was higher in group 2 patients than that in group 1 patients, and the difference was statistically significant (p < 0.01). Conclusions: the development of post-COVID-19 syndrome does not depend on the illness severity during the acute phase, and it may occur both in mild and moderate or severe cases. However, in the latter category the patients will have more symptoms. In patients recovered from COVID-19, most of the disease sequela were revealed in central nervous, bronchopulmonary, and cardiovascular systems. Comorbidities are associated with the severity of the novel coronavirus disease during the acute phase. COVID-19 survivors need follow-up care during the first three months after the acute phase and in the later period which should be provided by multidisciplinary team of specialists for achieving complete recovery of the patients’ health and improving the quality of life. KEYWORDS: coronavirus infection, COVID-19, post-COVID-19 syndrome, comorbidities, central nervous system disorders, bronchopul - monary system disorders, cardiovascular system disorders. FOR CITATION: Asfandiyarova N.S., Filippov E.V., Demikhov V.G. et al. Clinical manifestations of post-COVID-19 syndrome. Russian Medical Inquiry. 2022;6(11):612–617 (in Russ.). DOI: 10.32364/2587-6821-2022-6-11-612-617.