OBJECTIVE: To compare performance on the Assessment of Motor and Process Skills (AMPS), a measure of functional task performance and physiological responses (salivary cortisol levels) during AMPS administration, between typically developing children and children diagnosed with attention deficit hyperactivity disorder (ADHD). METHOD: In this quasi-experimental study, independent t tests, and mixed, repeated measures analysis of variance were conducted to compare a group of typically developing children (n = 21) with a group of children with ADHD (n = 12) on two dependent measures: (a) the AMPS and (b) salivary cortisol. Salivary cortisol, a stress hormone, was taken at three time points, baseline, mid-way through AMPS administration, and 20 min following AMPS administration. RESULTS: Significant differences were found on the activities of daily living (ADL) process ability measure of the AMPS (p = .001) and the ADL motor ability measure (p = .04), with the ADHD group performing more poorly than typical children. There was no significant group (ADHD vs. control) by time period interaction effect on cortisol levels. Overall, the cortisol levels of the ADHD group were higher than the levels of those in the control group (p = .02). Cortisol levels tended to drop significantly over time (p = .01) for both groups, however the patterns differed somewhat between groups. Cortisol levels of the typical children dropped at the final time period (20 min post-AMPS administration) whereas the levels of the children in the ADHD remained higher during this time period. This interaction effect approached, but did not reach, statistical significance (p = .15). CONCLUSION: The results of this investigation suggest that the AMPS is sensitive to detecting functional performance concerns, and both motor and process skill deficits, associated with ADHD, and therefore may be a useful assessment tool with this population. Data also suggests that cortisol expression to a well-known ADL task may be lower if the task is not overly challenging for the individual, and provides support for further study of the role of cortisol with disorders of attention.