Bioequivalence studies are the preliminary requirement for generic products to enter in the market. International regulatory authorities require that the final quality judgment of an oral dosage form be based on its in vitro dissolution profile and its in vivo bioavailability or bioequivalence evaluation. This is an open label, balanced, randomized, two treatments, two periods, two sequences, single dose, cross-over, and bioequivalence study in healthy, adult, subjects under fed conditions. Single oral dose of test formulation Tamsulosin HCl Capsules USP 0.4 mg (each hard gelatin capsule contains Tamsulosin HCl USP 0.4 mg) or reference formulation Flomax® (Tamsulosin hydrochloride) 0.4 mg was administered under lowlight with approximately 240 mL of drinking water at ambient temperature 30 min after initiation of a high fat calorie breakfast after an overnight fast of at least 10 hrs and not more than 12 hrs in period I. Similar procedure was followed in the II period of the study. All subjects finished the breakfast in 30 minutes or less. Subjects received alternate treatment in the subsequent period in such a way that each subject received both the treatments at the end of the study. Subjects received alternate treatments at the end of the study. The study was conducted according to the approved protocol, SOPs and ICH-GCP guidelines and applicable regulatory guidelines. A validated bio analytical method was adopted for conduct of analysis of the plasma samples of the study, which was selective, sensitive and cost effective. Based on geometric mean ratio of log transformed data and 90% confidence interval of test and reference product for Cmax, AUC0-t and AUC0-∞, it is concluded that the ratio and extent of absorption of test and reference product are similar.