Background: Severe postoperative pain is a major dilemma for patients undergoing abdominal aortic surgery. Transversus abdominis plane (TAP) block has been described a successful pain management technique after major abdominal surgery. Dexmedetomidine was proved to enhance the analgesic action of local anesthetics. Aim: This study was aimed to assess the impact of adding dexmedetomidine to levobupivacaine during TAP block in patients undergoing abdominal aortic operations. Patients and Methods: We included 114 patients in this prospective trial, and they were enrolled into two groups; the L group received levobupivacaine only, and the LD group received levobupivacaine plus dexmedetomidine. The block was performed before anesthetic induction. Postoperative pain score was our main outcome. Statistical Analysis: The collected data were tabulated and analyzed through the SPSS software program IBM's Statistical Package for the Social Sciences (SPSS) statistics for Windows (version 25, 2017) (IBM Corporation, Armonk, NY, USA). The categorical data were expressed as numbers and percentages and then compared using the Chi-square test. The continuous data were expressed as mean and standard deviation if normally distributed, or median and range if abnormally distributed. The former data were compared through the one-way ANOVA, while the latter were compared through the Kruskal–Wallis test. Any P < 0.05 was considered statistically significant. Results: Group LD showed significantly earlier sensory blocks compared to the other group. Postoperative pain scores were comparable between the two groups for the initial 4 h following the surgery. Adjuvant dexmedetomidine was associated with better pain scores for the subsequent 12 h compared to Group L. The duration till the first analgesic request showed a significant increase in the LD group (13.3 vs. 11.09 h in Group L). In addition, the same group showed a significant decline in their opioid consumption after the operation (48.95 μg vs. 72.63 μg in the other group). Postoperative nausea and vomiting were significantly increased in Group L. Conclusion: Adjuvant dexmedetomidine has a significant beneficial impact on postoperative analgesic profile. Its use as an adjuvant to peripheral and neuraxial nerve blocks should be recommended in pain management practice.