Abstarct: In the present study, a simple and efficient preconcentration method was proposed using two phase hollow fiber - liquid phase microextraction (HF-LPME) coupled with HPLC-UV(MWD) for simultaneous extraction and determination of trace amount of ticlopidine and losartan in tablet, serum and urine samples. 1- octanol was used as an extraction solvent with low volatility to prevent evaporation, low viscosity to ensure rapid mass transfer, low polarity to ensure compatibility with the hollow fiber, and to prevent leakage into the sample. Some parameters such as pH, extraction time, stirring rate, hollow fiber length and ionic strength as the effective factors in extraction's efficiency were optimized using experimental design.Under the optimized conditions; a linear calibration curve in the range of 0.004- 6.0 mg.L-1 for ticlopidine and 0.003- 5.5 mg.L-1 for losartan, with detection limit of 1.2 µg.L-1 for ticlopidine and 1.1 µg.L-1 for losartan and preconcentration factor of 272 for ticlopidine and 176 for losartan were achieved. The relative standard deviation for three replicate determinations of 0.1, 1.0 and 4.0 mg.L-1 were 3.56%, 3.95% and 1.70% for ticlopidine and 3.06%, 3.48% and 1.89% for losartan, respectively.