The metabolic and physiological consequences of three dietary levels of sodium (0.02, 0.11 and 0.18%) and chloride (0.10, 0.22 and 0.33%) were investigated. Corn, soybean meal and corn-gluten meal diets were formulated with varying levels of sodium and chloride. Pigs fed 0.02% sodium gained slower and less efficiently than pigs fed higher levels of sodium. Blood pH was not affected by either dietary sodium or chloride. Linear (P < 0.01) increases in HCO3, base excess (BE) and plasma sodium were observed when dietary sodium increased. Hemoglobin, plasma potassium, urea nitrogen, ornithine, lysine and total basic amino acids decreased linearly as dietary sodium increased. Blood hematocrit decreased curvilinearly (P < 0.05) with increasing dietary sodium. In addition, increasing dietary chloride linearly increased plasma potassium and decreased blood HCO3 and BE. A curvilinear response to dietary chloride was observed for hemoglobin. Dietary sodium influenced pigs’ growth and feed utilization as well as plasma electrolytes and basic amino acids. Although dietary chloride did influence plasma potassium and the buffering capacity of the blood, it had no effect on the rate and efficiency of weight gain of the pigs.