: We report a case of a 1-year-6-month old baby presenting with classic clinical of Prader-Willi syndrome, a rare congenital disorder. Early identification and multidisciplinary management are critical to improving outcomes. Case presentation: Patient U is a 1.5-year old male. Due to his inability to breastfeed for the first day after birth, diagnostic tests were initiated. He was dependent on tube feeding for over two months. At 9 months, the child was able to hold their head up and began sitting independently around 11 months. His eyes are slightly slanted, the bridge of his nose is narrow, the upper lip is thin, and the corners of his mouth are downturned.The skin soft texture. Muscle tone is noted to be weak. The size of the arms and feet is small. Additionally, the neck is of short stature. Cytogenetic Analysis: November 2023. The analysis identified a microdeletion in the 15q11-q13 chromosomal region. He was discharged from the hospital upon demonstrating the ability to suck effectively, achieving consistent weight gain, and having his sucking and swallowing activities adequately controlled. Discussion and Conclusion Prader-Willi syndrome is a genetic disorder resulting from the non-expression of a gene located on chromosome 15 at the 15q11.2–q13 region. The prevalence of corresponding to an approximate global total of 350,000 to 400,000 cases. The sex ratio is equivalent at 1:1. In the initial year of life (0–1 year), affected infants commonly present with muscle weakness, difficulties in feeding, reduced sucking capabilities, absence of crying or vomiting, diminished motor activity, poor muscle strength, and low weight. For individuals aged 1 to 10 years, symptoms encompass increased appetite, obesity, delays in speech and psychomotor development, a long facial structure, narrow forehead, downturned mouth and eyes, small hands and feet, along with other distinctive facial features. In adolescence and adulthood, prevalent symptoms may include behavioral changes, irritability, uncontrolled eating habits, diabetes, and depression. From infancy onward, holistic care may include nutritional interventions (such as tube feeding and specialized diets), strategies for heat retention, enhancement of sucking abilities. Cardiovascular and respiratory monitoring, weight management, physical activity support, health education for families and caregivers, growth hormone therapy, psychological counseling, sex hormone replacement therapy, and assistance with movement, psychomotor skills, cognitive and intellectual development, alongside speech therapy. Timely diagnosis, integrated multidisciplinary care, and proactive family involvement have the potential to markedly enhance the quality of life for affected individuals.