Objective To investigate the diagnosis and treatment of mesenteric cyst.Methods The clinical data of 5 patients with mesenteric cyst who were admitted to the First Affiliated Hospital of Harbin Medical University were retrospectively analyzed.The experiences in diagnosis,treatment and prognosis were summarized.Results Preoperative diagnosis of the mesenteric cyst mainly depended on imaging examination,such as color Doppler ultrasonography or computed tomography.The cysts of the 5 patients were located at the mesentery of the small intestine.All the patients received surgical resection of the cysts,and postoperative pathological examination confirmed the preoperative diagnosis.The duration of hospital stay was 8-12 days,and time of follow-up was 4-52 months,no recurrence nor canceration of the cysts was detected.Conclusions Color Doppler ultrasonography and computed tomography have high diagnostic value for mesenteric cyst,while its final diagnosis depends on pathological findings.Complete surgical resection is the first choice for the treatment of mesenteric cyst,and it provides a satisfactory prognosis for the patients.