Within medicine, few diagnoses have been subject to more debate than chronic fatigue syndrome (CFS). Despite consensus on the multifactorial nature of the problem [1,2], views about its aetiology are often divided, sadly not infrequently between doctor and patient. Both terminology and classification create potential confusion, by allowing multiple interpretations. Some patients prefer the label myalgic encephalomyelitis (ME), perhaps because of its biological connotation. Meanwhile, many doctors prefer ‘CFS’, because it lacks any aetiological assumptions. In practise, these labels are interchangeable and the term ‘CFS/ ME’ is frequently used. The ICD-10  classified ME as a neurological disorder under the code G93.3 (post-viral fatigue syndrome). CFS was listed in the alphabetical index as both neurological G93.3 (with ME if “chronic” or “post-viral”) and as a mental disorder under F.48 (neurasthenia), although the present online version lists G93.3 andR53 (malaise and fatigue, under general symptoms and signs).However, the entry forR53 lists exclusions including ‘fatigue syndrome’ (F48.0), and ‘post-viral fatigue syndrome’ (G93.3). By name and nosology, CFS can therefore be interpreted to be a neurological or mental disorder, reflecting perhaps the World Health Organisation's role as consensus-builder rather than final arbiter of aetiology, be it neurological or psychiatric . In fact, perhaps the single most cited argument in favour of the ‘biological’ position is that ME and (post-viral) CFS is classified as a neurological disorder in the ICD-10. The inference drawn from this is ME and CFS is due to an organic neurological disease process. One voice that has been absent from this debate is that of the group which might be expected to have the most informed view on whether or not CFS should be classified as a neurological condition— namely neurologists themselves.We report the first such survey of British neurologist's opinions.