Objective. To assess the analgesic efficacy of lornoxicam and compare it with that of tenoxicam in patients undergoing extracorporeal shock-wave lithotripsy (ESWL) for renal stones. Material and methods. The study was carried out in a randomized, double-blind fashion and involved 60 patients (American Society of Anesthesiologists physical status I-II) undergoing ESWL who were divided into three groups. Patients in the placebo group (n=20) received saline and those in the lornoxicam group (n=20) received lornoxicam 8 mg intravenously 60 min before the procedure. In the tenoxicam group, patients (n=20) received tenoxicam 20 mg intravenously at the same time point. All patients were started on patient-controlled i.v. meperidine analgesia during the procedure. The effectiveness was assessed by using a visual analog scale (VAS) and by calculating the total analgesic consumption of meperidine during the procedure. Arterial blood pressure, oxygen saturation, and respiratory rate were recorded throughout the procedure; nausea and vomiting, agitation, and respiratory depression were assessed. Results. Compared with patients in the placebo group, patients in the lornoxicam and tenoxicam groups received smaller doses of meperidine at all time points (p0.05). After 30, 45, and 60 min of ESWL, patients in the lornoxicam group required significantly smaller doses of meperidine than those in the tenoxicam group (p0.05). Patients in the placebo group showed higher VAS scores than those in the lornoxicam and tenoxicam groups at 15, 30 and 60 min. The VAS score in the lornoxicam group was lower than that in the tenoxicam group at 15, 30, and 45 min, but the difference between the groups was statistically significant only at 45 min (1 and 3, respectively; p0.05). Conclusion. In patients undergoing ESWL the i.v. administration of a single dose of 8 mg lornoxicam provides significantly better pain control compared with tenoxicam 20 mg and placebo, without increasing adverse side-effects.