BACKGROUND: Previous studies have shown that common headache triggers contribute to the onset of headache attacks on predisposed individuals and are considered important in the prevention of headache. The aim of this study was to compare the different characteristics of triggers among the most common primary headache subtypes (migraine without aura, migraine with aura and tension type headache). METHODS: A total of 116 headache patients of the neurology outpatient department of a tertiary hospital in Athens were selected according to the criteria of the International Classification of Headaches-3nd Edition Beta. Patients were interviewed using a questionnaire that contained 35 potential trigger factors. RESULTS: The findings showed that migraine and tension-type headache patients report multiple triggers, on a frequent but variable basis. The most frequent triggers reported by all subjects were stressful life events followed by intense emotions. The same applies to both genders, as well as the three headache subgroups. Patients suffering from migraine with aura reported the highest mean number of trigger per person and the highest frequency in almost all the trigger categories. Furthermore, patients with migraine with aura were more likely to report the following triggers: oversleeping, premenstrual period, stressful life events, hot/cold weather, relaxation after stress, menstruation, wind, intense emotions, shining, hunger and bright sunlight. These associations were mostly independent of the sociodemographic characteristics and the presence of anxiety or depressive symptoms. CONCLUSION: The sensitivity to trigger factors should be considered by both clinicians and headache sufferers.