A novel rapid, sensitive and reproducible High performance liquid chromatographic method was developed for quantitative determination of Efavirenz,, Lamivudine and Tenofovir Disoproxil Fumarate in active pharmaceutical ingredients and its dosageforms. The synthetic nucleoside reverse transcriptase inhibitor analogues Efavirenz, Lamivudine and Tenofovir Disoproxil Fumarate form one of the fixed dosage combinations used in HIV. It belongs to a group of anti-HIV medicines called nonnucleoside reverse transcriptase inhibitors (NNRTIs). The method is applicable to the quantification of related compounds of Efavirenz, Lamivudine and Tenofovir Disoproxil Fumarate form one of the fixed dosage combinations. Chromatographic separation of drugs from the possible impurities and the degradation products was achieved on an ACE C18, 250 x 4.6 mm, 5.0μm column; the gradient elution achieved with in 120.0 min. Dilute Ammonium Acetate as mobile phase A and Degassed mixture of Acetonitrile and Methanol (40 : 60) as mobile phase B . The flow rate was 1.5 ml/min, and the detection was done at 265nm. The above developed HPLC method was further subjected to hydrolytic, oxidative, photolytic and thermal stress conditions. The performance of the method was validated according to the present ICH guidelines for specificity, limit of detection, limit of quantification, linearity, accuracy, precision, and ruggedness.