We investigated the diagnostic usefulness of brain magnetic resonance imaging (MRI) screening in HIV-1-infected patients without neurological symptoms in detecting intracranial diseases at early stages. In this retrospective analysis, the study patients were HIV-1-infected patients who underwent brain MRI scan in clinical practice between 2001 and 2013. We excluded patients with MRI for (1) follow-up examination for prediagnosed intracranial diseases, (2) cancer staging, (3) screening mycobacterium/bacteria/fungi disease proliferation in the brain, and (4) evaluation for meningitis/encephalitis. The study patients (n=485) were classified into two groups: those who underwent brain MRI scan without any neurological symptoms/signs (asymptomatic patients, n=158) and those who underwent MRI due to such symptoms (symptomatic patients, n=327). Asymptomatic patients had lower CD4 counts than symptomatic patients (median 78 versus 241/μl). Intracranial diseases were detected in three (2%) of the asymptomatic patients [two toxoplasmosis and one progressive multifocal leukoencephalopathy (PML)] compared to 58 (19%) of the symptomatic patients (the χ(2) test, p<0.01). The latter included toxoplasmosis (n=10), PML (n=7), cytomegalovirus encephalitis (n=3), primary central nervous system lymphoma (n=3), cryptococcoma/meningitis (n=3), and HIV-associated dementia (n=17). Among symptomatic patients, intracranial diseases were common in those with slurred speech (3/6, 50%), seizure (4/10, 40%), eyesight/vision abnormality (5/16, 31%), altered mental status (8/31, 26%), and hemiplegia/numbness (13/50, 26%). For patients with CD4 count <200/μl, intracranial diseases were detected in only 3 (3%) of 144 asymptomatic patients, compared with 46 (32%) of 113 symptomatic patients (p<0.01). Brain MRI screening for HIV-1-infected patients without neurological symptoms is of little value.