The use of brain MRI for the diagnosis of neurological diseases has increased significantly over the past two decades. This has led to an increase in the discovery of chance findings, with asymptomatic lesions in the white matter being most frequent. Based on radiological criteria, these findings can be interpreted as demyelinating lesions in some cases. However, in the absence of clinical symptoms characteristic of multiple sclerosis (MS), a diagnosis of MS can’t be made in the patients with these incidental findings. These patients now met a diagnosis of radiologically isolated syndrome (RIS). Diagnostic and clinical approaches to patients with RIS are discussed in this article.