The objective of the study was to evaluate tamsulosin (TAM) efficacy in distal ureteral stone expulsion in Mexican patients. A double-blind clinical trial was carried out for a period of 4 weeks on 65 patients assigned to the following treatment groups: Group A, 32 patients receiving conventional treatment + TAM; and Group B, 33 patients receiving conventional treatment + placebo. Patients of both groups were checked every 14 days to evaluate treatment adherence and clinical progression through plain abdominal film and abdominal ultrasonogram. There was no significant difference in stone expulsion percentage between groups: Group A 69% (n = 22) versus Group B 70% (n = 23), P = 0.9. There was no significant difference in mean expulsion time comparison between groups: Group A 22 ± 6.7 days (11-30 days interval) versus Group B 23 ± 6.3 days (11-30 days interval), P = 0.3. Tamsulosin did not demonstrate greater efficacy in distal ureteral stone expulsion in Mexican patients.