Objective:To discuss the computed tomography (CT) and magnetic resonance (MR) imaging features of primary adrenal cortical carcinoma (PACC) and improve the imaging diagnostic level of primary adrenocortical carcinoma.Methods:The imaging features of 15 patients with biopsy or pathology confirmed PACC were retrospectively analiezed. There were 12 patients underwent CT examination, 7 patients underwent MR examination, and 4 patients underwent CT and MR exminations.Results:All of 15 PACCs were unilateral (10 on the right, 5 on the left). The maximum diameters of the lesions ranged from 4.4 to 15.1 (8.9±3.3)cm. The shape of the tumor was oval in 6 cases and irregular in 9 cases. CT findings: 1 cases showed homogeneous density and 11 cases were heterogeneous attenuation (including 2 cases with hemorrhage and 1 case with fat) on plain scan. The CT values of triple-phase of PACC ranged from 28.8 to 62.0(39.2±8.5)HU, 32.7 to 83.4(52.5±14.4)HU and 43.4 to 86.4(61.1±15.0)HU respectively. All cases showed mild (7 cases) and moderate (4 cases) gradual enhancement, only one case excluded. MRI findings: inhomogeneous mild and moderate enhancement were detected in 6 cases and homogeneneous enhancement was found in 1 case. The solid parts of PACC showed iso-signal intensity in T1WI, hyper-signal intensity in T2WI and diffusion limited in the diffusion weighted imaging (DWI). There were 14 cases of vascular shadow in 15 patients, and 3 cases of involvement and metastasis of surrounding tissues and organs.Conclusions:PACC often present as a big solitary heterogenous mass with necrotic area, hemorrhage and intratumoral vascular. The mild to moderate heterogenous gradual enhancement can be seen after the contrast.