Stroke is the third leading cause of death, after myocardial infarction and cancer, and the leading cause of permanent disability in Western countries. Although anti-inflammatory drugs have shown very promising results in preclinical rodent studies, they appeared to be ineffective against stroke in clinical trials. In this context, non-invasive detection of inflammatory cells after brain ischemia could be helpful (i) to select patients who may benefit from anti-inflammatory treatment, and/or (ii) to target an adequate individualized therapeutic time window. Magnetic resonance imaging (MRI) coupled with injection of iron oxide nanoparticles, a contrast agent taken up by macrophages ex vivo and in vivo, appears to be a promising tool for this purpose. This review focuses on the use of this technique to image inflammation in pre-clinical and clinical studies of stroke. Despite current limitations, MRI of inflammation may become an important tool for the investigation of novel ischemic stroke therapeutics targeting inflammation.