Objective To investigate the imaging features of CT and MRI in diagnosis of giant cell tumor of bone with aneurysmal bone cyst. Methods A case of giant cell tumor of bone with aneurysmal bone cyst confirmed by surgery and pathology in our hospital from January to March 2016 was enrolled in the study. The patient was examined with CT and MRI. Results CT scan showed different degrees of expansive changes and cortical thinning (or incomplete bony shell) in the patient. The typical features of CT were that the boundary between the bone cyst and primary lesion was not clear enough and the density was not uniform, including the primary lesion area (solid) and thin secondary lesion area. MRI imaging findings showed there was a low signal at the edge of lesion (incompleteness) in T1WI and T2WI scan , and the T1WI scan of main body of bone cyst indicated that there was a low or medium-high signal, and the T2WI scan showed a non-uniform high signal. The MRI enhanced scan showed that separate enhancement in lesion capsule wall and in lesions, and no obvious enhancement at the cystic site. The main body of lesion (primary giant cell tumor) showed medium and low signals in T1WI scan, and obviously low, medium and high mixed signals in T2WI. Conclusion CT and MRI images of giant cell tumor of bone with aneurysmal bone cyst are characteristic. MRI is superior to CT in the differential diagnosis of primary and secondary lesions. The combination with clinical manifestations of patients can significantly improve the diagnosis rate of the disease.