Since oral squamous cell carcinoma (OSCC) is one of the most important causes of death worldwide, the prevention and early detection plays a crucial role. Recent epidemiological studies have incriminated diabetes as a risk factor for the development of OSCC, as well as oral premalignant lesions. As for the last 20 years diabetes and oral squamous cell carcinoma rates have been increasing rapidly, therefore a reliable detection method of major saliva proteins as possible biomarkers for OSCC is of key priority. In this study we collected whole saliva samples from patients with diabetes and from healthy subjects. To reduce the risk of failure and to keep the investigation good reproducible, we proposed an examination and saliva collecting technique. The proteins were analyzed using SDS-PAGE and MALDI TOF/TOF mass spectrometry. Our findings show that the expression of Annexin A8, Peroxiredoxin-2 and Tyrosine kinase is elevated by patients having diabetes. All these proteins have been previously described in cancer saliva samples also in OSCC. Our current findings showed that testing saliva may be an effective and reliable method for detecting oral cancer in early stages.