This study aimed to evaluate the intake and food sources of sodium and potassium in 588 elementary school children in Chungnam province, South Korea. The participants were 145.3 cm tall and weighed 39.7 kg with an average body mass index of 19.0 kg/m(2). Daily energy intake was 1,640.1 kcal for boys and 1,643.9 kcal for girls, which was 86.3% and 96.7% of estimated energy requirements, respectively, and sodium intake was 3,465.7 mg for boys and 3,771.4 mg for girls, which was 266.6% and 290.1% of the adequate intake (AI), respectively (p < 0.05). Potassium intake was 1,981.2 mg for boys and 2,177.9 mg for girls, which was 61.9% and 68.1% of the Al (p < 0.05). The ratio of sodium to potassium intake was 1.7: 1. Both the boys and girls consumed sodium primarily from salt, kimchi, and salt-fermented shrimp and potassium primarily from rice, kimchi, milk, and pumpkin. In summary, South Korean elementary school students were found to have a 2.8 x higher intake of sodium than the AT and lower intake of potassium. It is important to emphasize the importance of reducing sodium and increasing potassium in the diet of elementary school children. Knowledge regarding the primary food sources of sodium and potassium may be used to tailor intervention efforts to reduce sodium intake and increase potassium intake.