Background: Several adjuvants have been used to improve the efficacy of transversus abdominis plane (TAP) block because it has been used as an effective component of multimodal analgesic treatment for infraumbilical surgeries. Here, we evaluated the effectiveness of dexamethasone as an additive to local anesthetic in TAP block for infraumbilical surgeries under general anesthesia in terms of time to first rescue analgesia, verbal numeric rating scale (VNRS) pain score, and mean total analgesic consumption over 24 hours. Materials and methods: This study was conducted on 60 adult patients who were randomly allocated into two groups of 30 patients each. In group A, 2 mL of normal saline and in group B, 8 mg (2 mL) dexamethasone was used with 20 mL of 0.25% ropivacaine in ultrasound (USG) guided TAP block bilaterally after induction of general anesthesia. Statistical analysis was done using chi-square test, Student\'s t-test, and Mann–Whitney U test. Results: The duration of analgesia was significantly longer in group B than group A (619.4 ± 21.4 minutes and 240.3 ± 18.6 minutes, respectively) (p < 0.001). VNRS was lower in both the groups, except at 4th, 5th, and 8th hours in group A and 12th hours in group B. Total mean analgesic consumption over 24 hours postoperatively was also significantly lower in group B than group A (p < 0.001). Conclusion: Using dexamethasone as an additive to 0.25% ropivacaine improves the efficacy of TAP block in terms of duration and quality of analgesia with significant reduction of postoperative analgesic requirement without any adverse effects.