The incidence of specific intracranial parenchymal lesions of HIV-infected patients varies considerably between countries. In the Republic of Korea, the number of HIV-infected patients is increasing, but little is known regarding the spectrum of intracranial parenchymal lesions in these patients. The aim of the present study was to obtain this information. To identify HIV patients with intracranial parenchymal lesions, the electronic database of radiological reports for 1,167 HIV-infected patients, seen from 1999 to 2008 at the Seoul National University Hospital, were reviewed. Neuroradiologic studies were performed on 165 of these patients, and intracranial parenchymal lesions were detected in 40 (3.4%) of them. Thirty-seven were male, and median age was 41 yr (range, 26-61). At the time of the diagnosis of intracranial parenchymal lesions, median CD4(+) lymphocyte count was 40 cells/microL (range 5-560) and in 33 (82.5%) patients, it was less than 200 cells/microL. Progressive multifocal leukoencephalopathy (12 patients) is the most frequent intracranial parenchymal lesions, followed by intracranial tuberculoma (7 patients), primary central nervous system lymphoma (7 patients), intracranial cryptococcoma (4 patients), Toxoplasma encephalitis (4 patients), and disseminated non-tuberculous mycobacterial infection (3 patients).