The primary purpose of this investigation was to compare 31 competitive female swimmers with 31 competitive male swimmers on their perceptual responses to submaximal swimming. A secondary purpose was to evaluate the relationship between heart rate (HR) and perceived exertion (RPE) in swimming. Each swimmer completed a 200-yd swim in his/her specialty stroke at 90% of the swimmer's current best time. Underwater and overhead pace lights were used to achieve an even pace during the swims, and HR was monitored by means of radiotelemetry. Ratings of overall and local perceived exertion were assessed immediately following each swim with Borg's 6-20 scale. ANOVA revealed no RPE differences across stroke classifications for the female or male swimmers, but local and overall RPE were lower (p < 0.01) in the females. Mean HR, however, was significantly higher (p < 0.05) for the female swimmers. Unlike research with other exercise modes, correlational analyses revealed that overall and local RPE were unrelated to HR (p > 0.05). Based on these findings, it is concluded that 1) female swimmers judged a paced swim to be less effortful than did male swimmers despite a greater objective strain in the females, and 2) HR was not correlated with perception of effort.