While cerebral cavernous malformations (CCMs) have been extensively described, few reports have described the imaging appearance of giant CCMs (GCCMs).To describe the imaging characteristics of GCCMs and study the reasons for preoperative misdiagnosis.We retrospectively analyzed the data of 12 patients (5 men, 7 women; mean age, 35.23 ± 12.64 years) with histopathologically confirmed GCCMs. Two radiologists analyzed the CT (n = 12) and MRI (n = 10) features: location, number, size, shape, boundary, signal intensity, and enhancement.The sellar region, cerebral hemisphere, skull bone, and ventricle were involved in 5, 4, 2, and 1 patients, respectively. Three tumors were irregularly shaped, while nine were oval. Eleven lesions showed slightly high- and/or high-density on CT; 1 lesion appeared as a low-density cyst. Calcifications were found in 11 lesions. Four tumors showed uniform hypointensity on T1-weighted imaging (T1WI) and hyperintense signals on T2-weighted imaging (T2WI). Six tumors showed mixed low-, equal-, and high-intensity signals on T1WI and T2WI. Noticeable contrast enhancement and gradual strengthening were noted on T1WI. Ten lesions showed hemorrhage and hemosiderin deposition. The GCCMs were wrongly diagnosed as cartilage-derived tumors/ meningioma (3 patients); tumor and hematoma (2 patients each); and pituitary tumor/ meningioma, chondroma, chordoma, ependymoma, and macroadenoma (1 patient each).GCCMs present as an oval mass with slightly high- and/or high-density calcifications on CT and show hemorrhage and hemosiderin accumulation on MRI. Therefore, slightly high- and/or high-density calcification and hemosiderin accumulation are critical clinical characteristics of GCCMs.Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.