"Peripheral ring enhancement" of intracranial lesions in the CT examination is still being considered as a specific manifestation for abscess or a cyst tumor. The author analysed 33 cases with peripheral ring enhancement and concluded that although most of brain abscesses, metastatic brain tumors and cystic astrocytomas might demonstrate it, it was not specific for any diseases. To reach the correct diagnosis, it is necessary to collect and analyse the clinical features, laboratory data, and follow-up CT in addition to present CT findings. Examples of the various types of lesions that demonstrate peripheral ring enhancement are shown. It is suggested that various pathology could demonstrate "ring enhancement lesion", if CT scan were done at a fortuitous time. Some differential diagnostic suggestions are also made.