Xerostomia and salivary gland hypofunction impact oral health and quality of life and are mainly caused by the intake of medications, chronic disorders like Sjögren's syndrome, and head and neck radiation. Other aetiologies may be local diseases of the salivary glands including infections, cancer, or obstructive diseases of the salivary ducts. Management strategies are primarily alleviating symptoms. Current investigations show promising results in stem cell treatment. In this review, we want to provide comprehension of the aetiologies, evaluation, and management of xerostomia and hyposalivation.