The present invention provides a method of diagnosis of stroke or the possibility thereof in a subject suspected of suffering from stroke, comprising subjecting a sample of body fluid taken from the subject to mass spectrometry to determine a test amount of a polypeptide in the sample, wherein the polypeptide is differentially contained in the body fluid of stroke-affected subjects and non-stroke-affected subjects, and has a molecular weight in the range of from 3000 to 30000 Da; and determining whether the test amount is consistent with a diagnosis of stroke. The test amount can also be used to determine the type of stroke that is diagnosed, in particular whether it is of the ischemic or hemorrhagic type. The invention also provides use of the polypeptides for diagnostic, prognostic and therapeutic applications. The invention further provides a kit for use in diagnosis of stroke, comprising a probe for receiving a sample of body fluid, and for placement in a mass spectrometer, thereby to determine a test amount of a polypeptide in the sample, wherein the polypeptide is differentially contained in the body fluid of stroke-affected subjects and non-stroke-affected subjects, and has a molecular weight in the range of from 3000 to 30000 Da.