The aim of this article is to review the problem of xerostomia considering its clinical, etiological, diagnostic and treatment features, basing on the today's tutorials and scientific articles found in databases on the Internet. Recent epidemiologic data on the prevalence of xerostomia in different countries are introduced. There are analyzed the main aspects of clinical manifestations of xerostomia, according to the different etiology analyzed. The most common etiological factors causing xerostomia, especially the main three of them: radiation therapy, Sjögren's syndrome, and drugs, are pointed out. The most popular and accepted clinical and laboratory assays for measuring and evaluating the function of salivary glands are represented. Attention is paid to xerostomia as substantiation of the separate diagnosis and its role in diagnosing other diseases. The concept of possible treatment modalities and prognosis are discussed. The main and most common problems concerning xerostomia are revealed.