Post-traumatic headache (PTH) is an important public health issue - head injuries are common, headache is the most common sequelae of head injuries, and PTH can be particularly disabling. Fortunately, for most individuals with PTH, the headache gradually dissipates over a period of several days, weeks, or months either spontaneously or aided by non-pharmacologic and/or pharmacologic management. Regrettably, for a minority of head-injured individuals, the PTH is intractable and disabling despite aggressive and comprehensive treatment. Unfortunately, there are many prejudices against individuals with PTH. Frequently, the presence or absence of litigation and/or the mechanism of head injury (sports-related trauma, slip-and-fall injury, motor vehicle accident, or military service-related injury) biases physicians' views on the legitimacy of the patient's PTH. Accordingly, this review attempts to summarize the state of the art of our understanding of PTH. This clinical review highlights: (a) views on PTH throughout the last few centuries, (b) the ICHD-2 classification of PTH, (c) the epidemiology of head injuries and PTH, (d) the clinical characteristics of PTH, (e) PTH related postconcussive symptoms, (f) pathophysiology of PTH, (g) evaluation of PTH, and (h) management of PTH.