Objective: To investigate changes in postural sway while standing, walking parameters, and performance of functional tasks during rehabilitation in a group of traumatic brain injury (TBI) patients. Design: Descriptive. Setting: Inpatient brain injury rehabilitation unit. Participants: Thirteen subjects undergoing rehabilitation after severe TBI. Outcome Measures: Two assessments were performed, 2 to 6 weeks apart that included the following: postural sway in three stance conditions; temporal and spatial parameters of walking; functional assessments of walking, standing up, reaching while standing, and stair climbing. Results: There were significant reductions in postural sway in all stance conditions (p < .05) and significant increases in velocity of walking (p < .05), stride length (p < .01), and left and right step lengths (p < .01). Performance on all functional tasks improved (p < .05) except for functional reach. There were no significant correlations between changes in postural sway and changes in walking parameters or functional assessments. Conclusion: This study demonstrated significant improvements in postural sway, walking parameters, and functional tasks during a relatively short period of rehabilitation after severe TBI. Improvements in standing balance appear to be independent of improvements in walking performance, suggesting that different mechanisms underlie improved control of these tasks.