Dentine hypersensitivity is a prevalent, painful condition of the teeth. Despite the fact that the accuracy of the terminology is questionable and other terms have been proposed, 'dentine hypersensitivity' has been in long-term use and is, therefore, the preferred term. In dentine hypersensitiv-ity, lesions exhibit patent tubules at the exposed dentine surface and appropriate stimuli trigger pulpal nerves via a hydrodynamic mechanorecep-tor mechanism to produce a typically short, sharp, painful response. This accepted definition of the condition indicates the need to consider a differential diagnosis. This review will consider evidence that dentine hyper-sensitivity is a tooth-wear phenomenon characterised predominantly by erosion, which both exposes dentine and, more importantly, initiates the lesions. Abrasion caused by brushing teeth with toothpaste appears to be a secondary aggravating factor, which may even act in synergy with erosion. Gingival recession probably accounts for most dentine exposure at the gingival margin, but the process is poorly understood. Management strate-gies, which take into account aetiological and predisposing factors, rather than treatment alone, should be considered. There is little clinical research on many aspects of the aetiology and particularly on the management of the condition. In 1982, dentine hypersensitivity was described as an enigma, because it was frequently encountered yet poorly understood 1 . Some 20 years later, it is worthwhile reconsidering the statement, as the title of a recent article seems to suggest 2 . This review will discuss the terminology, definition, epidemiology, mecha-nisms, anatomy, aetiology and management of the condition. It is hoped that it will demonstrate that, although dentine hypersensitivity is not the enigma it once was, there is still much to be discovered about the condition, its prevention and its management.