To evaluate and compare the efficacy of tamsulosin (0.4mg, once/day) and combinations of it with trospium (20mg, twice/day) in the treatment of single small lower ureteral stones.A total of 126 patients presenting to urology outpatient clinics from July 2012 to May 2015, with a single 5–10mm sized lower ureteral stone were randomly classified into two treatment groups. Patients in group A (n=62) received an oral dose of 0.4mg tamsulosin once daily and 20mg trospium chloride twice daily. Patients in group B (n=64) received 0.4mg tamsulosin once daily and placebo twice daily. The spontaneous passage of stones, the stone expulsion time, and adverse effects were evaluated.There were no significant differences in baseline characteristic of the patients in both groups. Stone expulsion was observed in 47 patients (75.8%), and 58 (90.62%) in groups A and B respectively. The average time to expulsion was 11.65±5.32days in group A and 17.35±6.21days in group B. The spontaneous stone passage rate through the ureter was significantly higher and the stone expulsion time was faster in groups A than in group B (p<0.05). The adverse effects observed in both groups were comparable and were mild.The combination of 0.4mg tamsulosin and 40mg trospium as MET for single lower ureteral stones <10mm is safe and more effective than 0.4mg tamsulosin as a mono-therapy.