Background: Diabetes mellitus (DM) is a chronic disease of the carbohydrate metabolism that, when not rigorously controlled, compromises systemic and organ integrity, thereby causing renal diseases, blindness, neuropathy, arteriosclerosis, infections, and glandular dysfunction, including the salivary glands. The aim of this study was to determine the relationship between the qualitative and quantitative parameters of salivary alteration, which are indicators of salivary gland dysfunction, and the level of metabolic control of type 2 diabetes patients. Material and Methods: A convenience sample of 74 voluntary patients with type 2 DM was selected, each of whom donated a sample of unstimulated saliva. Salivary parameters such as salivary flow rate, protein concentration, pH, and xerostomia were studied. Results: There is a positive relationship between the level of metabolic control measured with HbA1 and the protein concentration in saliva (Spearman rho = 0.329 and p = 0.004). The same assay showed an inverse correlation between HbA1 and pH (Spearman rho = -0.225 and p = 0.05). Conclusions: The protein concentration in saliva and, to a lesser extent, the pH may be useful as glandular dysfunction indicators in DM2 patients.