Normal and alloxan-diabetic rats were injected submucously in the posterior region of the upper jaw with bupivacaine (1.28 mg/kg) containing adrenaline (0.0012 mg/kg), or lignocaine (5.14 mg/kg) containing noradrenaline (0.005 mg/kg). Blood glucose was determined at zero (before administration), 0.5, 1, 2, 3 and 4 hours after the administration of the anesthetics. Statistical analysis (ANOVA and Tukey's test, P < 0.05) showed significant differences between treatments at 1 hour in normal rats. Bupivacaine with adrenaline induced a significantly greater blood glucose level than lignocaine with noradrenaline. The effect was significant but of short duration. In alloxan-diabetic rats, anesthetics containing adrenaline or noradrenaline did not induce increased blood glucose levels.