In a psychophysiological investigation of tension headache cases (n = 23) with migraine headache controls (n = 10) and non-headache controls (n = 30), both tonic and phasic activity of the key muscles (frontalis and temporalis) and the temporal artery pulse were examined. Although all headache cases had significantly elevated levels of temporalis tension, tension headache sufferers were not differentiated from migraine in this respect. A substantial subgroup of tension sufferers (30%) had no detectable muscular or arterial abnormality associated with their severe pain. Idiosyncratic stress stimuli evoked significant frontalis reactivity in all headache cases (tension and migraine). These responses were triggered only by potent stimuli. Migraine cases had higher level of temporal artery abnormality at rest, in response to stress, and during pain episodes than tension cases. The implications of these results were discussed with respect to the prevailing view of tension headaches. An alternative model of this disorder was considered.