Introduction: The study of the process of premature aging as a pathological condition, with clarification of its pathogenetic and clinical manifestations, as well as the systematization of this knowledge contribute to the development of methods for diagnosing and correcting age-related changes. Objective: To develop and justify a classification variant for morphotypes of premature aging among women with undifferentiated connective tissue dysplasia (UCTD). Materials and Methods: Stage 1 - Analysis of medical documentation (n=1560) to identify women with phenotypic manifestations of UCTD (4 or more systems, according to clinical recommendations). Stage 2 - Three groups were formed: MASS-like/marphanoid phenotype (Group 1, n=44, average age 38.1±6.2 years), Ehlers-Danlos-like phenotype/hypermobile joints (Group 2, n=41, average age 37.3±6.3 years), and a comparison group (2 or fewer manifestations of UCTD, n=36, average age 36.4±5.6 years). Pregnant, breastfeeding women, those in menopause, and individuals with differentiated forms of CTD were excluded. Signs of skin aging, aging type, anthropometric data of face and body, and microcirculation were assessed using conjunctival biomicroscopy. Statistical data processing was conducted using parametric methods in IBM SPSS Statistics v.27. Differences were considered statistically significant at pen Groups 1 and 2 were statistically significant (pcal Index of Aging Symptoms Scale was observed in Group 1 – 16.1±0.06 points (p about clinical manifestations of UCTD and their connection to premature aging. Conclusions: Two-thirds of the patients were diagnosed with various external or internal phenotypic manifestations of UCTD, while 25.9% had clinical syndromes of UCTD involving four main systems of the body. Based on the identified clinical signs of premature aging during UCTD, anthropometric data, and microcirculation disorders, a classification variant for premature aging during UCTD has been proposed, including marfanoid and Ehlers-Danlos-like morphotypes.