Saliva is a complex biofluid with functions important for preserving the health of the oral cavity. Aat the same time, it can be used as a diagnostic sample for detecting numerous pathological conditions. Saliva contains so-called biomarkers that can reflect the state of the organism in the oral cavity. Due to its advantages – cost-effectiveness, non-invasiveness, ease of collection and storage – it is increasingly mentioned as a potential blood substitute in the diagnosis of local and systemic diseases. The possible methods of collecting saliva samples are numerous and can be divided depending on the type of saliva (glandular or whole saliva) and stimulation status (stimulated or unstimulated saliva). However, the choice of method is extremely important because of the possible influence on the qualitative and quantitative properties of saliva. Salivaomics is a scientific field encompassing the research, identification, and isolation of biomarkers with the aim of diagnosing diseases in a timely manner, selecting an adequate method of treatment and subsequently monitoring the patient's condition. It can be divided into five major branches – proteomics, genomics, transcriptomics, metabolomics and microbiomics.