The correlation of specific headache attack characteristics derived from a standardized questionnaire was studied in a consecutive series of 392 patients attending a headache clinic. In patients reporting headache with aura such attacks tended to be infrequent, and the percentage of their headache attacks that were preceded by aura varied widely, many cases having very low percentages. Paresthesias as auras were uncommon and rarely occurred without visual aura. Unilateral headaches were associated with nausea to widely varying degrees. Most patients reported both unilateral headache and headache with tension characteristics. Definite history of hypertension was significantly correlated specifically with migraine with aura (classic migraine).