Two methods for the simultaneous determination of Emtricitabine and Tenofovir by spectroscopy have been developed. These two simple, accurate and precise methods include Area Under the Curve (AUC) method and Dual Wavelength Method. From a solvent effect studies and the spectral behaviours of Emtricitabine and Tenofovir, methanol was selected as solvent. Emtricitabine shows maximum absorbance at 281 nm and Tenofovir shows maximum absorbance at 259 nm. For the AUC method, the wavelength ranges between 242-248 nm and 269-275 nm were selected with reference to the absorbance curves plotted between the wavelengths of 200-400 nm. In the second method i.e. Dual method in which two wavelengths were selected for each drug in a way so that the difference in absorbance is zero for another drug. Emtricitabine shows equal absorbance at 230.696 nm and 250 nm, where the differences in absorbance were measured for the determination of Tenofovir. Similarly, differences in absorbances at 250 nm and 268.670 nm were measured for determination of Emtricitabine. These methods allows rapid analysis of two drug combination. The results of analysis were validated statistically and by recovery studies. This tablet containing both drugs was assayed using the methods developed, showing a good accuracy and precision. © 2010.