Objectives The objective of the study was to determine the effect of a single dose of IV dexamethasone on postoperative pain in patients after laparoscopic cholecystectomy. The outcome will be measured in the terms of mean pain score. Study design and setting This is a prospective study. We did a randomized control trial to compare the outcome in two groups. This study was conducted in the Department of Surgery, Benazir Bhutto Hospital, Rawalpindi, from December 2021 to May 2022. The total duration of the study was six months. Methodology A total of 160 patients were randomly divided into group A and group B. We performed laparoscopic cholecystectomies on all the patients under standard general anesthesia. In group A (control group), 5 mL of normal saline was injected intravenously at the time of induction of anesthesia. In group B, the dexamethasone group, the inj. dexamethasone with a dose of 0.1 mg/kg diluted in 5 mL normal saline was given intravenously at the time of induction of anesthesia. Postoperatively, the median pain score was measured using visual analog scale (VAS) at 2, 6, 12, and 24 h on a specially made proforma. The results were further stratified according to gender and age. Results The postoperative VAS in group B was significantly low compared with group A when measured at 2, 6, 12, and 24 h. It means that the median pain score was markedly less in the study group than in the placebo one, and it was statistically significant (p<0.05). Conclusion Administration of a single dose of dexamethasone preoperatively in laparoscopic cholecystectomy patients is effective to control postoperative pain.