Simple, rapid, accurate, precise and economical UV-spectrophotometric methods have been developed and validated for simultaneous estimation of Aspirin and Lansoprazole in a Synthetic mixture. The first method is the Q-Absorption ratio method, which involves formation of Q-absorption equation at 299.2 nm (isoabsorptive point) for Aspirin and Lansoprazole  and also at 276.6 nm (λmax of Aspirin). The Second method is Dual Wavelength Method. The method was based on determination of Aspirin at the absorbance difference between 272.28 nm and 286.41 nm and Lansoprazole at the absorbance difference between 269.20 nm and 294 nm. Developed methods were validated according to ICH Q2 (R1) guidelines. The methods were found to be linear between the range of 33.3-166.6 µg/ml for Aspirin and 5-25µg/ml for Lansoprazole for both methods. The precision (intra-day, inter-day) of methods were found within limits (RSD