An accurate, specific and precise UV spectrophotometric method was developed for the simultaneous determination of lansoprazole and naproxen. The indicating proposed method was accurate and precise for simultaneous estimation of NAP and LAN in tablet dosage form by using Simultaneous Equation. Materials used were UV- - Visible Spectrometer (LAB INDIA 3200) with 1cm quartz cells. An analytical balance (Roy electronics – LCBCNS) was used for weighing the samples. Means, standard deviation (SD), relative standard deviation (RSD) and linear regression analysis were calculated using Microsoft Excel 2007. The maximum wavelength (λmax) was found to be 284 nm for LAN and 271 nm for NAP. The linearity was found to be 10-35μg/ml (r2 =0·999) for NAP and 5-30μg/ml (r2=0·998) for LAN. Validation was performed as ICH guidelines for Linearity, accuracy, precision, LOD and LOQ. The limit of quantification of NAP was found to be 0·15μg/ml and for LAN was 1·7μg/ml. The limit of detection of NAP was found to be 0·04μg/ml and for LAN was 0·5μg/ml. The % recovery was found to be satisfactory. The proposed method is simple, sensitive and reproducible for simultaneous determination of UV Spectrophotometric method for lansoprazole and Naproxen in tablet dosage form.