Hemicrania continua (HC) is a primary headache disorder that is characterized by a continuous unilateral headache of moderate severity, exacerbations of severe pain, and complete responsiveness to indomethacin. Misdiagnosis of HC is probably common in general neurology settings and other clinical specialties. This paper is an attempt to bridge the gap between the correct and misdiagnosis of this disorder. HC was once thought to be a rare headache disorder, but is, in fact, an under-recognized headache syndrome. HC can be of continuous or remitting form. Variants such as HC with aura have been described and secondary cases may occur. Indomethacin is the best treatment, although HC could respond to other NSAIDs, such as the selective COX-2 inhibitors.