A rapid and sensitive liquid chromatography tandem mass spectrometry (LC-MS/MS) method has been developed for quantitative determination of Tamsulosin (TMS). The analyte was extracted from human plasma by Liquid-Liquid Extraction (LLE) using Methyl Tertiary Butyl Ether (MTBE) and Dichloromethane (DCM). Tolteridone Tartrate (TLT) was used as the internal standard. A Phenomenex RP-18 (50 x 4.6 mm i.d., 5µ) column provided chromatographic separation of the analyte using a mobile phase containing Acetonitrile: 0.01M ammonium formate (pH9.0) (90:10) at a flow rate of 0.8 ml/min with an elution time as low as 3.0 min which was followed by detection with mass spectrometry. The Multiple Reaction Monitoring (MRM) pair (m/z) 409.3/271.4 for TMS and 326.4/147.1 for TLT. Simple isocratic chromatographic conditions and mass spectrometric detection of the method enables the detection of TMS at less than nanogram levels. The proposed method was found to be linear from 0.20-100.08 ng/ ml. The precision and accuracy values are within 10%. The overall recovery of TMS was 90.92 %.