The purpose of this investigation was to compare the effects of oral and intravenous saline rehydration on differentiated ratings of perceived exertion(RPE) and thirst. Eight men underwent three randomly assigned rehydration treatments following a 2- to 4-h exercise-induced dehydration bout to reduce body weight by 4%. Treatments included 0.45% saline infusion (IV), 0.45% saline oral ingestion (ORAL), and no fluid (NF). Following rehydration and rest (2 h total), subjects walked at 50% ˙VO2max for 90 min at 36°C (EX). Central RPE during ORAL was lower (P < 0.05) than IV and NF throughout EX. Local RPE during NF was higher (P < 0.05) than IV and ORAL at minutes 20 and 40 of EX and overall RPE during NF was higher (P < 0.05) than ORAL at minutes 20 and 40 of EX. Significant correlations were found between overall RPE and mean skin temperature for IV (r = 0.72) and NF (r = 0.75), and between overall RPE and thirst ratings for IV (r = 0.70). Thirst ratings were not different among trials at postdehydration. Following rehydration, thirst was higher(P < 0.05) during NF than IV and ORAL and lower (P < 0.05) during ORAL than IV at all subsequent time points. Results suggest that oral rehydration is likely to elicit lower RPE and thirst ratings compared with intravenous rehydration.