Our retrospective study was aimed at determining the existence of weekend headache and, if so, whether it has the same clinical features as migraine without aura and episodic tension-type headache, or whether it occurs as a separate form of headache which could find its own place in the International Headache Society classification. For this study, we reviewed the clinical records of 120 patients with migraine without aura and 120 patients with episodic tension-type headache randomly selected among all those referred to the Headache Center of the University of Parma Institute of Neurology between 1985 and 1996. A review of these records suggests that weekend headache exists for both types of headache considered. Clinically, it is interesting to note that the male-to-female ratio for the weekend form of tension-type headache was 1:1, as opposed to 1:3 for general episodic tension-type headache. As regards classification, no evidence so far seems to suggest that weekend headache should be considered as an independent entity. Apart from certain features that appear to be peculiar to this form of headache-such as increased pain intensity-it thoroughly fulfills the diagnostic criteria of the primary headaches from which it evolves. Finally, a few clinical features suggest that the weekend may simply be a triggering factor in migraine without aura attacks, while playing a major role in episodic tension-type headache. However, weekend headache is a clinical entity that clearly needs further study.