Increasing efferent renal sympathetic nerve activity (ERSNA) increases afferent renal nerve activity (ARNA) which decreases ERSNA to prevent sodium retention. High sodium diet enhances ARNA suggesting an important role for ARNA in suppressing ERSNA during excess sodium intake. Mean arterial pressure (MAP) is elevated in afferent renal denervated (DRX) rats fed high sodium diet. We examined whether the increased MAP in DRX is due to impaired arterial baroreflex function. In DRX and ShamDRX rats fed high sodium diet, arterial baroreflex function was determined in conscious rats by i.v. nitroprusside and phenylephrine or calculations of transfer function gain from arterial pressure to ERSNA (spontaneous baroreflex sensitivity). Increasing MAP did not suppress ERSNA to the same extent in DRX as in ShamDRX, -60±4 vs., -77±6%. Maximum gain, -4.22±0.45 vs., -6.04±0.90 %ERSNA/mm Hg, and the maximum value of instantaneous gain, -4.19±0.45 vs., -6.04±0.81 % ERSNA/mm Hg, were less in DRX than in ShamDRX. Likewise, transfer function gain was lower in DRX than in ShamDRX, 3.9±0.2 vs., 6.1±0.5 NU/mmHg. Reflex nerve stimulation by air jet stress produced greater increases in ERSNA in DRX than in ShamDRX, 35,000±4900 vs., 20,900±3,410 %•sec (AUC). Likewise, the ERSNA responses to thermal cutaneous stimulation were greater in DRX than in ShamDRX. These studies suggest impaired suppression of ERSNA in DRX. There were no differences in arterial baroreflex function in DRX and ShamDRX fed normal sodium diet. Conclusion: impaired baroreflex function contributes to increased ERSNA which would eventually lead to sodium retention and increased MAP in DRX rats fed high sodium diet.