Diffuse or multifocal ischaemic white matter lesions increase the risk of intracranial haemorrhage in patients using oral anticoagulants for secondary prevention after cerebral ischaemia of arterial origin. We studied whether neurologists could reliably assess the presence of these white matter abnormalities. As part of the European/Australian Stroke Prevention in Reversible Ischaemia Trial (ESPRIT), the severity of white matter lesions and presence of ischaemic lesions were twice assessed in a consensus meeting of three neurologists (from a pool of nine) as absent, moderate or severe, in a sample of 126 randomly selected CT or MRI scans. The neurologists were not aware of the duplicate grading. The degree of agreement between the first and second observation was calculated with kappa statistics. The kappa value for agreement between the first and second assessment of white matter lesions was 0.58 (95% CI 0.40–0.76). The kappa value for the presence of clinically relevant and/or irrelevant ischaemic lesions was 0.68 (95% CI 0.58–0.78). Clinicians can assess the presence of white matter lesions with sufficient reliability. Such assessment may prevent unnecessary risk with oral anticoagulation in secondary prevention after cerebral ischaemia of arterial origin, of which the efficacy is currently being assessed in ESPRIT.