The proximates, vitamin C, minerals, and fatty acids of five potato cultivars were evaluated by AOAC methods, the hydrazine method, ICP-AES, and gas chromatography, respectively. The proximate analyses; vitamin C, reducing sugar, and soluble solid contents; and mineral and fatty acid compositions were significantly different among the five cultivars. The Superior cultivar contained a higher carbohydrate content and higher Ca/P ratio and lower levels of crude protein and Na. The Atlantic cultivar contained significantly higher amount of energy, carbohydrate, reducing sugar, vitamin C, SEA, and MUFA, and significantly lower amount of minerals and PUFA. The Shepody cultivar contained significantly higher amount of carbohydrate and MUFA, and significantly lower amount of soluble solid, vitamin C, and SFA. In addition, the P, Fe, Mg, Cu, and Al levels were significantly higher in Shepody, and Zn content was significantly lower. The Jopung cultivar contained significantly higher levels of moisture and Na, and significantly lower levels of soluble content, reducing sugar, carbohydrate, crude protein, and fat. Finally, the Namsuh cultivar contained significantly higher amount of soluble solid, crude protein, K, Mg, and Al, and significantly lower amount of reducing sugar.