The role of nucleus tractus solitarius (NTS) in cardiovascular system regulation is controversial. On the other hand, the problem of hypertension in diabetic animals is the subject of many research programs. The aim of present study was to determine whether inactivation of NTS could affect blood pressure and heart rate in diabetic rats. To this end, stereptozotocin induced diabetic rats were anesthetized with urethane and a cannula was inserted above NTS. Blood pressure and heart rate were monitored by using an intra-arterial cannula. Lidocaine (0.5 ml, %2) was injected unilaterally through a single injection cannula aimed at the NTS for functional ablation. Sham control diabetic group received saline. The results indicated that inactivation of NTS in diabetic rats has no effect on systolic and mean arterial pressure but enhances diastolic pressure (P<0.05). There was no significant difference in heart rate between sham control and test groups. It is concluded that NTS has a decremental effect on diastolic pressure in diabetes.