Objective To analyze the clinical characteristics and treatment methods of primary intestinal lymphangiectasia (PIL) in infants and to improve clinical diagnosis and treatment. Methods A retrospective analysis was conducted on the clinical manifestations, laboratory tests, nuclear imaging examinations and treatment methods of four cases of PIL in infants admitted to the Department of Lymphatic Surgery at Beijing Shijitan Hospital from October 2012 to December 2013. The diagnosis and treatment of infantile PIL were summarized based on long term follow-up results. Results The patients aged 4-9 months and are all female. All 4 patients presented with diarrhea as the initial symptom, accompanied by symmetrical edema of the lower limbs, and 3 cases were complicated with respiratory infections. Laboratory tests showed a decrease in absolute values of blood lymphocytes, albumin, and globulin. Four patients presented with mild anemia, hypocalcemia, and iron deficiency. Radionuclide imaging indicated loss of intestinal proteins. Four patients were treated with liver protection, protein supplementation, dieresis and total parenteral nutrition for 3-4 weeks. After discharge, personalized medium chain triglycerides (MCT) dietary treatment was administered for 3-30 months. Following up for 10 years, 4 patients resumed normal diet and had normal blood albumin levels rechecked, with no recurrence. Conclusions Infant PIL is relatively rare, with clinical manifestations mainly characterized by diarrhea and edema, it is often accompanied by respiratory infections. Electrolyte disorders, such as hypocalcemia and iron deficiency, are more common. In infant patients suspected of PIL, radioactive nuclide testing may serve as the first choice for definitive diagnosis A sufficient course of total parenteral nutrition in conjunction with personalized MCT diet is an effective treatment for PIL in infants.