Xerostomia or dry mouth is a condition that is frequently encountered in dental practice. The most common cause is the use of certain systemic medications, which make the elderly at greater risk because they are usually more medicated. Other causes include high doses of radiation and certain diseases such as Sjogren's syndrome. Xerostomia is associated with difficulties in chewing, swallowing, tasting or speaking. This results in poor diet, malnutrition and decreased social interaction. Xerostomia can cause oral discomfort, especially for denture wearers. Patients are at increased risk of developing dental caries. A thorough intraoral and extra-oral clinical examination is important for diagnosis. Treatment may include the use of salivary substitutes (Biotene), salivary stimulants such as pilocarpine, ongoing dental care, caries prevention, a review of the current prescription drug regimen and possible elimination of drugs having anticholinergic effects. Because of the ageing population, and the concomitant increase in medicated individuals, dentists can expect to be presented with xerostomia in an increasing number of patients in the coming years and therefore should be familiar with its diagnosis and treatment. Therefore, the purpose of this review is to outline for clinicians the common aetiologies, clinical identification, and routine therapeutic modalities available for individuals with xerostomia.