This study examined whether (1) short-term maximal aerobic exercise to exhaustion affects Simple Reaction Time, Visual Spatial Memory, Continual Processing (attention), Code Substitution (short-term memory), and Working Memory over time and between groups and (2) exercise intensity and chronic aerobic activity in young healthy women affect cognitive performance. As women are an understudied population, cognitive function in apparently healthy active (n = 9) and sedentary (n = 9) 18- to 25-yr.-old female college students was evaluated before, during, and after a short-term maximal bout of treadmill running and compared with that of nonexercising, age-matched controls (n = 8). Selected cognitive variables were assessed prior to, directly after VO2max, and after a recovery from VO2max, and working memory was assessed at 25%, 50%, 75%, and 100% of each individual's VO2max. Analysis showed simple reaction time was faster in Active than in Sedentary women but was not affected by exercise. Working memory declined during and immediately after short-term maximal exercise but improved after recovery from the exercise. Short-term maximal treadmill exercise was associated with reduced Working Memory performance during exercise and improved Working Memory after recovery.