Objective To study the X-ray and CT features of costal eosinophilic granuloma for a better understanding.Methods Eight patients with costal eosinophilic granuloma proved by surgery or biopsy were analyzed retrospectively.All patients had X-ray plain film, 6 patients had CT examination,including a case of enhanced CT scan.Results All 8 lesions were solitary.Six lesions were in the anterior rib and 2 in the posterior rib.On X-ray, all case showed single cavity and oval lesion with clear boundary.On CT images, 5 lesions demonstrated expansile destruction of bone with cortical bone thinning, and 3 were osteolystic destruction with soft tissue mass around.On the patient with enhanced CT scan, the lesions showed a moderate and uniform enhancement.Conclusion The X-ray and CT findings of costal eosinophilic granuloma are characteristic.