The objective of the present study was to comparatively evaluate the concentrations of blood and salivary glucose as well as salivary flow and xerostomia in type 2 diabetic and non-diabetic patients. The mean salivary glucose level in diabetic patients was 14.03 ±16.76 mg/dl and 6.35 ± 6.02 mg/dl (P = 0.036) in the control group. The mean capillary blood glucose level in diabetic patients was 213 ± 88 mg/dl, while that in non-diabetic patients was 99 ± 14 mg/dl (P = 0.000). The mean value for resting salivary flow was 0.21 ± 0.16 ml/min in diabetic patients and 0.33 ± 0.20 ml/min in the control group (P = 0.002). The stimulated salivary flow was lower in the group of diabetic patients, with a mean of 0.63 ± 0.43 ml/min, whereas the control group showed a mean of 1.20 ± 0.70 ml/min (P = 0.000). Of the diabetic patients, 45% exhibited hyposalivation, in contrast to 2.5% of the non-diabetic patients (P = 0.000). Xerostomia was reported in 12.5% of diabetic patients and 5% of non-diabetic patients (P = 0.23). We can conclude that salivary glucose concentration was significantly higher in the experimental group and that there was no correlation between salivary and blood glucose concentrations in diabetic patients. The total salivary flow was significantly reduced in diabetic patients and there was no significant difference as to the presence of xerostomia in both groups. (J Oral Sci 52, 293-298, 2010)