Objective Cardiovascular aneurysm is an extremely rare and serious complication of Behcet syndrome (BS) in children, lacking clinical specificity and with very few studies. This study aims to explore the clinical characteristics and treatment strategies of BS complicated with aneurysms in children. Methods A retrospective analysis was conducted on the clinical data of 3 children with BS complicated with aneurysms who were admitted to hospital from December 2018 to March 2023. Results A total of 36 children with BS were included during the same period, among whom 3 patients (8.3%) developed aneurysms, including 2 boys and 1 girl. The age range of BS onset was 5 to 13 years old, and the time of aneurysm discovery was 2 months to 5 years after the onset of BS. Two cases involved pulmonary artery aneurysms (PAAs) with in-situ thrombosis, while one had an aneurysm at the right coronary sinus of the aorta. All patients presented with concurrent vascular pathologies (deep vein thrombosis, pulmonary arterial thrombosis, and aortic dissection). At aneurysm detection, all exhibited fever and elevated inflammatory markers, with no gastrointestinal involvement. All three patients were treated with corticosteroids combined with immunosuppressants (cyclophosphamide/methotrexate) and biologics (TNF-α inhibitors/tocilizumab), among whom two patients received surgical intervention (left lower lobectomy in Case 1 and Bentall procedure in Case 2). Following medical therapy, Cases 1 and 3 achieved extravascular stability, but PAAs showed no regression. During corticosteroid tapering, Cases 1 and 2 experienced recurrence with new organ damage (Case 1 involved the nervous system, and Case 2 involved the skin, heart, and intestines). Conclusions In children with BS, pulmonary artery aneurysms are the most common type of arterial aneurysm involvement. The condition often has an insidious onset and is frequently associated with other vascular lesions. Regular vascular imaging screening is recommended for children with elevated inflammatory markers and no gastrointestinal involvement. Treatment should be individualized, potentially combining immunosuppressive therapy and surgical intervention, as some cases exhibit steroid dependence.