BACKGROUND: The COVID-19 pandemic remains an urgent medical and socio-economic problem. The symptoms, signs and complications of COVID-19 in the acute phase of the disease are now well known, while the long-term consequences of the disease continue to be studied. AIM: The aim of this study was to study the frequency, clinical manifestations of “prolonged” COVID-19 and post-covid syndrome in advanced and old ages people treated in a hospital. MATERIALS AND METHODS: The study included patients aged over 75 years old diagnosed with COVID-19 who were treated in two multidisciplinary hospitals in Moscow in 2021–2022: 94 patients aged 75 to 94 years, including 75.5% of women. At the stage of inpatient treatment, patients were interviewed and medical records were analyzed with registration of demographic data, comorbidities, clinical symptoms and signs of the disease, laboratory markers, complications, and treatment outcome. After 1 and 12 months. after discharge, among the survivors, they were interviewed by telephone interview using a special questionnaire with registration of complaints, repeated hospitalizations and complications of COVID-19, assessment of their psycho-emotional state and identification of cognitive-behavioral disorders. RESULTS: In 70.2% of cases, the disease proceeded in a severe and extremely severe form. The majority of patients before COVID-19 had chronic diseases, most often arterial hypertension (85.9%), chronic heart failure (45.7%) and diabetes mellitus (27.2%). Hospital mortality was 22.6%. Poll after 1 month performed in 41/70 surviving patients (58.6%). Among the symptoms, the most common were fainting (41.5%), palpitations (36.6%), constipation (34.1%), the appearance or increase of shortness of breath (31.7%). Almost every day, 14.6%, 12.2% and 14.6% of the respondents experienced stress, anxiety and apathy. Difficulties in performing hygiene procedures, self-care, dressing were observed in 19.5, 12.2 and 12.2% of cases, respectively; 36.6% experienced severe problems when walking long distances. Poll after 12 months performed in 34/70 people (51.4%). Among the symptoms, the most frequently recorded were behavioral changes (32.4%), increased blood pressure (26.5%), problems with vision (26.5%) and hearing (23.5%). Psycho-emotional disorders were detected less frequently: 2 patients (5.9%) experienced daily stress, 1 respondent (2.9%) was worried about strong agitation and apathy. Difficulties in dressing, performing hygiene procedures, self-care were experienced by 32.4, 29.4 and 8.8% of patients; 20.6% experienced severe problems when walking long distances. CONCLUSIONS: The conducted study indicates a high prevalence of symptoms of “prolonged” COVID-19 and post-covid syndrome in elderly people and the duration of their persistence, which may limit their functional activity and negatively affect the quality of life.