This study was performed to document the frequency, duration and types of symptoms of postdrome in migraine patients. Eight hundred and twenty-seven consecutive headache clinic patients (IHS 1.1, 1.2 and 1.5.1) were evaluated at first visit. Postdrome frequency, duration and characteristics were analysed. Sixty-eight per cent of 827 patients reported postdrome (69.1% females; 56.8% males, P<0.007). The average duration of the postdrome was 25.2 h. Fifty-six per cent had postdrome for <or=12 h, 32% for 12-24 h, 88% for <or=24 h, and 12% for >24 h. The commonest symptoms were tiredness (71.8%), head pain (33.1%), cognitive difficulties (11.7%), 'hangover' (10.7%), gastrointestinal symptoms (8.4%), mood change (6.8%), and weakness (6.2%). Patients with postdrome compared with patients without postdrome have more characteristic and more frequent migraine features. This study demonstrated postdrome in 68% of patients, duration<or=24 h in most patients, more often associated with a full-blown migraine attack, more common in females, and with commonest symptoms being tiredness and low-grade headache.