Background: Catheter-related bladder discomfort (CRBD) is a frequent complaint after awakening from anesthesia in patients receiving perioperative bladder catheterization. Overactive bladder (OAB) and CRBD show similar symptoms; thus, drugs used for the management of OAB influence symptoms of CRBD. Trospium chloride has been found effective in managing resistant cases of OAB. We evaluated the efficacy of oral trospium on CRBD in the postoperative period. Methods: Sixty-four male and female adult patients, with planned spinal surgery and requiring urinary bladder catheterization, were randomly divided into two groups of 32 each. Group T patients received 60 mg extended-release oral trospium (extended-release) 1 h before induction of anesthesia and Group C patients received a similar-looking placebo. The anesthetic technique was identical in both groups. The CRBD score was evaluated in the postoperative ward using a 4-point scale (1 = no discomfort, 2 = mild, 3 = moderate, 4 = severe). Readings were recorded on arrival (0 h), and 1 h, 2 h, and 6 h postoperatively. All patients received fentanyl for postoperative pain relief. Results: The incidence of CRBD was significantly higher in group C than in group T at 0 h (66% vs 22%, P=0.001) and 1 h postoperatively (72% vs 28%, P=0.001). The incidence of moderate to severe CRBD was higher in group C at postoperative 2 h (82% vs 14%, P=0.004). There was no significant difference in postoperative fentanyl requirements. Conclusions Pretreatment with 60 mg ER trospium reduced the incidence and severity of CRBD in the early postoperative period.