We investigated the prevalence of headache in a group of patients attending a psychiatric clinic because suffering from panic disorder, according to DSM-IV criteria. The psychopathological assessment was performed with the 'Panic Disorder/Agoraphobia Questionnaire' and the presence of headache was evaluated according to the criteria of the International Headache Society. The results showed that two-thirds of patients met the criteria for a diagnosis of headache, with migraine without aura being the most frequent form, followed by tension headache, while two patients only were affected by migraine with aura. When we compared panic patients with and without headache, those with headache had a longer duration of panic disorder, a higher number of attacks and a heavier family loading for panic disorder and headache. This suggests that the comorbidity of headache with panic disorder renders this condition more severe and possibly responsive to different treatments compared to panic disorder alone.