The role of mandibular dysfunction in the etiology of headache is still underestimated in the medical literature. For this reason an analysis of own questionnaire investigations published in the years 1983 to 1999 was done. These investigations were carried out in 3915 subjects aged 15-66. In order to determine the prevalence of headache associated with mandibular dysfunction in the analysis mandibular parafunctions and clicking in the temporomandibular joints (TMJs) were selected. The comparison of the prevalence of headache in groups with and without mandibular parafunctions and in groups with and without clicking in the TMJs has shown that the prevalence of headache was significantly higher in groups with mandibular parafunctions and with clicking in the TMJs than in groups without these disturbances. The difference in the prevalence of headache in the investigated groups has shown that headaches noted in the population can be associated with mandibular parafunctions in 18.2% and dependent on the age with clicking in the TMJs in 9.7% to 25%.