A simple , specific, accurate and precise RP-HPLC method was developed for determination of Irbesartan (IRB) in pharmaceutical dosage forms in tablets products and sachet using symmetry (L 1 ) column at 30°C . The signal was detected at 225 nm. A mobile phase dissolve 0.5 g of buffer potassium phosphate in 100 ml distilled water and adjust pH 2.7 , methanol and acetonitrile at ratio (40 :30 :30 ) . and flow rate 1.2ml/min -1 at pH=7.2 a mobile phase The percent recovery was detected 101 % and the linearity of concentration was 10-50 µg.ml -1 and supported this method by using (FT.I.R.) spectrum method for organic spectrophotometer to prove the chemical structure of this drug and some physical properties . we are obtained the result is identical of other literature . The proposed method was applied successfully for determination of the IRB in tablets products.