Dehorning is a painful animal management procedure that is commonly performed in dairy calves. The use of local anesthesia lessens the physiological and behavioral effects of dehorning in calves. Twenty-four intact Holstein heifer calves (6 to 8 wk of age) were assigned to 1 of 4 treatments (n = 6 calves/treatment) to evaluate effects of timing of local anesthesia on physiological indicators of stress associated with pain of dehorning. Treatments included: anesthesia without dehorning (CON); dehorning without anesthesia (NO_ANET); anesthesia followed by immediate dehorning (ANET_0); and anesthesia with a 10-min delay before dehorning (ANET_10). Approximately 2 h before dehorning, jugular catheters (14 gauge, 3.5 inch; MILA International, Inc., Erlanger, KY) were inserted. Blood samples were collected 10 min before and immediately before (0-min sample) the initiation of the experiment. For the groups that received local anesthesia, a cornual nerve block was performed with 5 mL of 2% lidocaine hydrochloride on both horns. In NO_ANET, calves received 5 mL of 0.9% saline in place of lidocaine. Blood samples were collected at 1, 2, 3, 4, 5, 10, 15, 20, 25, 30, 40, 50, 60, 90, and 120 after dehorning. Plasma concentrations were measured by radioimmunoassay for cortisol at every time point and adrenocorticotropic hormone (ACTH) through 30 min. At 25 min after dehorning, cortisol concentrations were lower (P < 0.05) in CON than ANET_0, whereas ANET_10 and NO_ANET were not significantly different from either CON or ANET_0. At 1 and 2 min post-dehorning, ACTH concentrations were lower (P < 0.05) in ANET_10 and CON than ANET_0 and NO_ANET. At 3, 4, 5, and 10 min post-dehorning, ACTH concentrations were lower in CON than ANET_0 and NO_ANET, and ANET_10 did not differ significantly from any treatment groups. Because the observed differences in plasma ACTH concentrations dissipated within 5 min and plasma cortisol concentrations returned to pretreatment levels within 1 h of dehorning for all calves, it is inconclusive as to whether or not there is a benefit to waiting 10 min after the administration of lidocaine to dehorn calves.