Our purpose is to distinguish the nature of fatigue in people poststroke and to identify potential contributing factors using physiological and psychological measures. Poststroke fatigue is a prevalent, yet commonly neglected, issue. It can impact daily functions and quality of life and has been associated with a higher fatality rate. Previous studies have acknowledged the multidimensional nature of poststroke fatigue, identifying potential contributing factors such as aerobic fitness capacity, motor control ability, and depression. However, few studies have examined these factors using quantifiable functional measurements. Here, twelve people poststroke were recruited (5 males, mean age=58.5 ± 10.6 years; mean poststroke-time=48 ± 45 months). Participants were asked to walk as far as they could for 6 minutes to induce acute fatigue, followed immediately by a self-reported Acute Fatigue index in addition to a maximal-effort graded-exercise and a motor control test. A fatigue severity scale was used to assess chronic fatigue, and a depression scale was used to record depressive symptoms. Using Pearson’s product-moment correlation coefficient, acute fatigue showed a statistically significant negative correlation with aerobic fitness (r=-.709, p=.01) and a moderate negative correlation with motor control (r=-.473, p=.121). Chronic fatigue showed a strong correlation with depression (r=.963, p=.173). Our findings suggest that aerobic fitness may be a key contributing factor to acute fatigue.