Abstract Background Poorly controlled acute pain after abdominal surgery is related to somatic pain signals derived from the abdominal wall and is associated with a variety of unwanted post- operative consequences, including patient suffering, distress, respiratory complications, delirium, myocardial ischemia, prolonged hospital stay, an increased likelihood of chronic pain, increased consumption of analgesics, delayed bowel function and increase the requirement for rescue analgesics. Appropriate pain treatment protocols to reduce postoperative morbidity, improve the results of the surgery and decrease hospital costs. Aim of the Work The aim of this study is to evaluate the effect of adding dexamethasone as a perineural adjuvant on the post operative duration of action of Transversus Abdominus Plane (TAP) block in patients undergoing appendectomy. Patients and Methods The study was conducted on 30 randomly chosen patients aged 17 to 55 years, American Society of Anesthesiologists (ASA) class I or II scheduled for appendectomy under general anesthesia in Ain Shams University Hospitals after approval of the medical ethical committee. They were allocated in two groups of 15 patients each: Results Dexamethasone as an adjuvant to LA has been shown to prolong the duration of pain-free period, less requirement for rescue opioids consumption, more patient satisfaction. A similar finding was observed in our study. Conclusion The addition of dexamethasone to bupivacaine in TAP block in appendectomy provides a prolonged duration of postoperative analgesia, with reduced analgesic requirements, a better quality of analgesia in terms of VAS score compared to bupivacaine alone group.