To assess the global impact of episodic headaches in patients consulting general practitioners (GPs) using the Headache Impact Test (HIT-6) questionnaire, and to compare this with measures of headache severity and quality of life. A total of 2802 patients consulting 349 GPs participated to this cross-sectional study. Data were collected on headache severity using the Migraine Severity (MIGSEV) scale, headache impact with the HIT-6 and quality of life with the Qualité de Vie et Migraine (QVM) questionnaire. Diagnosis was assigned retrospectively according to the International Headache Society criteria. The association between the HIT-6 scale and the other scales was determined from a Pearson's chi-square test, an analysis of variance and Spearman correlation coefficients. Patients (2537) provided exploitable data. Six percent of the sample had little impact, 14% moderate, 14% substantial and 66% severe impact. The HIT-6 scores were significantly different between diagnostic groups, being highest in the migraine group. The HIT-6 score were well correlated with headache severity and QVM score. The HIT-6 scale correlates, across different diagnostic groups of headache, with both headache severity and with quality of life.