Because salivary gland function and morphology can be changed by a variety of diseases and drugs, the process of clinically assessing and diagnosing salivary gland changes in patients suspected of having Sjögren's syndrome (SS) must include not just clinical recognition of the problem and assessment of its nature and severity, but identification of the cause. Determining the presence of the salivary component of SS in a patient suspected of having the disease involves three types of observations: (1) eliciting symptoms and observing signs suggesting decreased salivary function (xerostomia) during the examination, (2) objectively assessing functional or anatomical salivary changes with different types of clinical procedures that are not necessarily disease-specific, and (3) applying the most disease-specific procedures as diagnostic criteria to determine the cause of the problem. Currently used diagnostic criteria for the salivary component of SS are reviewed and compared. Alternative diagnostic criteria should be avoided if they substitute non-specific tests for more disease-specific tests. There is as yet no perfect diagnostic criterion for the salivary component of SS, but significant focal sialadenitis in a labial salivary gland biopsy is the best in terms of its disease specificity, convenience, availability and low risk.