There is a growing interest in diagnosis based on the analysis of saliva. This is a simple, non-invasive method of obtaining oral samples which is safe for both the health worker and the patient, not to mention allowing for simple and cost-efficient storage. The majority of studies use general saliva samples in their entirety, complex fluids containing both local and systemic sources and whose composition corresponds to that of the blood. General saliva contains a considerable amount of desquamated epithelial cells, microorganisms and remnants of food and drink; it is essential to cleanse and refine the saliva samples to remove any external elements. Immediate processing of the sample is recommended in order to avoid decomposition, where this is not possible, the sample may be stored at -80ºC. Salivary analysis - much the same as blood analysis - aims to identify diverse medication or indications of certain diseases while providing a relatively simple tool for both early diagnosis and monitoring various irregularities. The practicalities of salivary analysis have been studied in fields such as: viral and bacterial infections, autoimmune diseases (like Sjögren's syndrome and cɶliac disease), endocrinopathies (such as Cushing's syndrome), oncology (early diagnosis of breast, lung and stomach carcinoma and oral squamous cell carcinoma), stress assessment, medication detection and forensic science among others. It is hoped that salivary analysis, with the help of current technological advances, will be valued much more highly in the near future. There still remain contradictory results with respect to analytic markers, which is why further studies into wider-ranging samples are fundamental to prove its viability. Key words:Saliva, biomarkers, early diagnosis.