Chronic short–lasting headaches, in which trigeminal autonomic cephalalgias (TACs) are included, are relatively rare syndromes and not always well recognised. We present a case highly suggestive of short–lasting unilateral neuralgiform headache with conjunctival injection and tearing (SUNCT) and we try to affirm essential points to distinguish the diagnosis from other TACs and chronic short–lasting headaches. We conclude that the qualifying points for differential diagnosis are number and duration of attacks in a day, presence of autonomic features and lack of indomethacin effect.