A striking feature of migraine is the difference between the estimated migraine prevalence and the actual number of migraineurs consulting their general practitioners (GPs). We investigated the impact of a sensitisation campaign on migraine in a large cohort of patients, living in a district of Rome. The study involved 10 GPs and a population of about 12 000 people, contacted by mail and posters located in GP clinics. Both the letter and poster stressed the impact of headache on quality of life and included the Italian version of the three-item Identification of Migraine (ID Migraine) screening test, consisting of questions on disability, nausea and photophobia. If the subjects suffered from headaches, they were invited to contact their GPs for a visit and a free consultation with a headache expert. By means of this sensitisation campaign, 195 headache patients consulted their GPs. Ninety-two percent of them (n=179) were migraineurs; 73% of them had never consulted a physician for headache. The ID Migraine test had a sensitivity of 0.92 (95% CI 0.86–0.95), a specificity of 0.75 (95% CI 0.47–0.91) and a positive predictive value (PPV) of 0.97 (95% CI 0.93–0.99) for a clinical diagnosis of migraine, according to the International Headache Society (IHS) criteria. This study confirms that a large number of migraine patients never see a doctor for their headache. This awareness campaign is likely to identify the severest cases of undiagnosed migraineurs. However, mailing campaigns do not seem to be so effective in bringing undiagnosed migraine patients into the primary care setting, and more efficient strategies have to be planned.