Dental erosion is one of the most common dental diseases and it is a growing problem. Numerous epidemiological studies have investigated the prevalence of dental erosion. For these studies different cross sections of the population are investigated. Large differences were found between countries, geographic locations and age groups. Most prevalence data is available from European studies and it is estimated that 29 % of the adults is affected by tooth wear. Next to geographical differences there are large differences per age group and the highest prevalence (11-100 %) was found in children between 9 and 17 years old. Studies with adults aged 18-88 years showed prevalence between 4 and 83 %. There is evidence that the prevalence of erosion is growing steadily, especially in the older age group. Furthermore, it is suggested that gastro-oesophageal reflux disease (GERD) is an important aggravating factor of dental erosion. Erosive wear is most common on, but not limited to, occlusal and palatal surfaces of the teeth. The occlusal erosions are often found on first mandibular molars. Lingually located lesions are most common on the palatal surfaces of the maxillary anterior teeth, and are often linked to intrinsic erosion.