A reversed-phase (RP) liquid chromatographic technique for the simultaneous determination of aliskiren (ALS), amlodipine (AMD) and hydrochlorothiazide (HCT) in spiked human plasma and urine is presented. The method employs a gradient elution using 10 mM orthophosphoric acid containing 0.1% triethylamine (pH 2.5, v/v) and acetonitrile and an RP-C-18 column (4.6 mm x 250 mm, 5 mu m, Phenomenex) at 1 mL/min of flow rate, with a UV photo diode array detector at 271 nm. The linear ranges were 0.01-10 mu g/mL in plasma and 0.05-10 mu g/mL in urine for both ALS and AMD. The linearty of HCT was in the range of 0.0125-2.5 mu g/mL in plasma and urine. Correlation coefficients (r (2)) were higher than 0.9983 for all of the analytes, indicating good linear relationship. The method validation was performed with respect to linearity, recovery, accuracy, precision and stability. The developed method could be applied in the routine clinical analysis.