In the past two decades, the demographic crisis in Bulgaria has been widely debated. According to the National Statistical Institute (NSI), the proportion of people aged 65 and over is increasing, despite the general population decline in the country. To investigate whether the age structure of patients operated on has changed during the past 10 years and assess the need to reorganize the training of anesthetists,aretrospective study in the anesthesia electronic database of the University Hospital in Rouse was carried out. The data of anesthesia performed by anesthesiologists in 2005, 2010 and 2015 in patients aged 65 and over were summarized. The distribution of these patients by ASA Physical Classification System and frequency of complications during anesthesia were analyzed. The average annual number of anaesthesias for the three years was almost unchanged and amounted to about 5500. The proportion of patients aged 65 and over increased from 30.54%in 2005 to 35.72%in 2010, and 37.81%in 2015. The distribution of patients in according to the ASA Classification changed significantly: the percentage of patients ASAI-IIdropped from 36.19%in 2005 to 11.85%in 2015. The patients in the ASA III-IVgroups for the three analyzed years was 41.86%, 58.66%and 65.30%, respectively, and this was mainly due to the increase in the ASAIVpatients. It is necessary to build multidisciplinary teams and prepare specialized protocols for behavior in geriatric patients. It is imperative that anesthesiologists possess specialized knowledge about age-related organ changes and their effects on anesthesia.