Medication overuse headache is a common feature underlying chronic headache, especially migraine. It also represents a major therapeutic challenge, especially in headache specialty clinics where it can represent the majority of patients. The syndrome remains under-diagnosed and the role of symptomatic medication overuse underestimated. Physicians should be properly educated in this area of pain, for prevention of this too often intractable syndrome could be improved. The basis of therapy is discontinuance of the abused medication. Additional treatment relies on a multifaceted approach that embraces management of psychiatric comorbidities and emphasizes patient education. Various pharmacological regimens, abortive and prophylactic, are available. Further scientific study is warranted to elucidate the ultimate mechanisms of this syndrome and define more effective treatments. This article gives detailed clinical description, tentative pathophysiologic explanation and therapeutic suggestions.