The Jebsen Hand Function Test (JHFT) is a standardized assessment that has been used as a clinical outcome measure. To appropriately interpret the effects of an intervention on hand function (as measured by the JHFT), the extent to which this instrument shows significant practice effects must be quantified. The purpose of this study was to determine whether the JHFT is susceptible to within-session practice effects. The results showed that the dominant and nondominant hands significantly improved on the JHFT and many of its subtests over six consecutive trials. Although practice effects might complicate the interpretation of change due to intervention, we briefly relate our findings to emerging neuropsychological evidence that practice effects may indicate a person’s motor learning potential or treatment responsiveness.