The aims of this study were to objectively measure the physical performance and physical endurance of patients with traumatic brain injury with minimization of cognitive and psychological fatigue, and to compare the physical performance of brain injured patients with that of healthy controls. This was a nonrandomized partially blinded controlled study. The study setting was the Outpatient Multidisciplinary Brain Injury Clinic in the Department of Physical Medicine and Rehabilitation of a tertiary care university teaching hospital. Participants included an experimental group that comprised independently ambulant men (age 18-55 years) with mild-to-moderate traumatic brain injury (n = 24) who complained of greater fatigue than before their injury and an age-matched and sex-matched control group (n = 24). The intervention included the Six-Minute Walk Test. The primary outcome measures were the Six-Minute Walk Distance, the Fatigue Severity Scale, Addenbrooke's Cognitive Examination, and the Fatigue Visual Numeric Scale; the secondary outcome measures were the Physiological Cost Index of Walking and the Borg Scale of Perceived Exertion. The Six-Minute Walk Distance of the experimental group (452.33[plus or minus]68.816) when compared with that of the control group (518.08[plus or minus]92.114) was reduced by 12.7 and 30.5%, respectively, when compared with the predicted Six-Minute Walking Distance (650.04[plus or minus]79.142) for the same age and sex. The mean Fatigue Severity Scale values were 2.51 and 1.62 for the experimental and control groups, respectively. The mean Addenbrooke's Cognitive Examination Score for the patients was 85.5[plus or minus]7.265. In conclusion, the Six-Minute Walk Test is useful in segregating physical fatigue from cognitive and psychological aspects of fatigue when cognitive and psychological dimensions are known. The Six-Minute Walk Test can be used as a tool for exercise intensity prescription in men with mild-to-moderate brain injury, to avoid the deleterious effects of fatigue.