OBJECTIVE The aim of this study was to compare the efficacy and safety of 3 nonsteroidal anti-inflammatory drugs-intravenous tenoxicam, lornoxicam, and dexketoprofen trometamol-for the treatment of patients with renal colic. METHODS We conducted a prospective double-blind randomized trial of consecutive adult patients who presented to the emergency department with a chief complaint of acute flank pain and had a clinical diagnosis of suspected acute renal colic. Patients were randomly allocated to receive an intravenous bolus of tenoxicam, lornoxicam, or dexketoprofen trometamol in a blinded fashion. Primary outcome measure of the study was visual analog scale (VAS) score difference at 30 minutes. Secondary outcome measures were VAS scores at 5, 15, and 120 minutes as well as rescue analgesic need at 30 minutes and adverse events during the follow-up period. RESULTS A total of 445 patients were screened, and 123 patients were enrolled in the study. The mean age was 36 ± 10 years. The mean reduction in VAS pain scores at 30 minutes was 42 ± 26 mm for tenoxicam, 57 ± 23 mm for lornoxicam, and 52 ± 25 mm for dexketoprofen (P = .047). Lornoxicam demonstrated the fastest rate of VAS score reduction over the first 30 minutes. The mean reduction values in VAS pain scores at 5, 15, and 120 minutes were similar among the 3 groups. Rescue analgesics at 30 minutes were required by 16 patients (39%) receiving tenoxicam, 10 patients (24%) receiving lornoxicam, and 8 patients (19%) receiving dexketoprofen (P = .121). No serious adverse events were observed. CONCLUSIONS Intravenous tenoxicam, lornoxicam, and dexketoprofen are all effective in the treatment of renal colic, although lornoxicam appears to reduce VAS pain scores with the fastest rate in this comparison.