Background: Gastrointestinal stromal tumors (GISTs) account for 1 to 3% of all primary malignant tumors of the gastrointestinal tract. The global incidence of GISTs varies in the range of 7-15 cases per 1 million people per year. In about 95% of cases, the incidence is sporadic. Despite the fact that some success has been achieved in the treatment of this pathology, the problem of GISTs treatment is urgent, especially in elderly and senile patients in particular. The aim of the study: To study the age-related characteristics of GISTs development in patients of older age groups. Materials and methods: A retrospective analysis of 56 clinical cases of GISTs in patients of different age groups according to the WHO classification was carried out in the study. Results: The most common variant of the immunohistochemical structure was the spindle cell one – 62.5%. In most cases, tumors were localized in the stomach – 82.2%. Elderly patients had larger tumor sizes compared with young and middle-aged patients. In patients of older age groups, the disease was most often detected at stage II. In most cases, a comorbid pathology was detected, most often a combination of several diseases of the cardiovascular system. Conclusion: In patients of older age groups, the spindle cell structure of the GISTs is most common, the tumor was most often localized in the stomach (77.4%), most often the tumor was localized along the lesser curvature. In most cases, the tumor was up to 10.0 cm in diameter. On average, the disease was detected at stage II. Comorbid pathology occurred in 87.3% of cases. In 2020-2021, the disease was detected more often, the of tumors sizes were smaller, due to an increase in the number of CT scans of the chest for the diagnosis of the new coronavirus infection.