Taro and yam are used for different purposes mainly used in south western region in Ethiopia especially in Benchmaji, Keffa and Sheka zones of the country and are underutilized foods for nutrition and income in other parts of the Ethiopia. Traditionally, it has been believed that a cure for hyper tension that is used to minimize the hyper tension, as a snack and etc. Therefore Promoting and supporting the use of taro and yam can make a major contribution to the food security of Ethiopia and of the world as well. The present study focused on, the quantitative determination of proximate compositions of the taro and yam samples cultivated in southwestern Ethiopia (Keffa zone, Benchmaji zone and Sheka zone). The parameters investigated were proximate composition (crude protein, crude fat, crude fibre, carbohydrate, and energy). Proximate compositions were determined by Association of Official Analytical Chemists (AOAC, 2000).The result indicated that, the proximate composition of both raw taro and yam samples in this study were: Crude Protein (4.03-6.22, 3.30-6.44%), crude fat (0.77-1.26, 0.71-1.30%), crude fibre (3.45-5.74, 2.47-4.39%), total ash (2.53-4.82, 1.76-3.27%), utilizable Carbohydrates (77.82-81.18, 75.98-84.07%) and Gross energy (338.79-351.63, 330.12-353.64) Kcal/100g, respectively. Thus, in general, both raw taro and yam had appreciable amount of the proximate composition, and could be a promising crops for securing food supply in the study area under investigation.