Can salivary free radicals and antioxidant parameters be useful in general diagnosis and evaluation of diabetes mellitus Type II (DM)? Serum and salivary redox state of 40 diabetes mellitus patients were examined and compared with 20 controls. The involvement of salivary gland in diabetes mellitus has been suggested based on salivary flow rate and compositional alterations. In addition, the redox state of saliva of diabetes mellitus patients is different than that of normoglycemic control human subjects. This observation unveils the opportunity to use noninvasive saliva-based diagnostics for diabetes mellitus patients.