Objective: The objective of the study was to determine whether ideational apraxia (IA), a loss of ability to plan the sequence of actions needed to achieve a goal, is associated with Parkinson disease (PD). Background: The frontal lobes play an important role in planning and sequencing, and many patients with PD have frontal lobe dysfunction. Methods: Ten right-handed patients with PD and 10 right-handed neurologically and psychiatrically healthy people participated. To assess for IA, participants were given sets of pictures that showed the steps in completing a task, but the steps were shown out of order. The participants were required to point to the pictures in the correct sequence to complete each task. The participants also performed a control task of sequencing randomly arranged printed single words to create a sentence that described an accompanying picture. Results: The patients with PD performed more poorly than the controls on the action-sequencing tasks (P<0.05). Errors were predominantly in sequencing rather than repetition or omission, indicating that the poor performance was not caused by perseveration. There were no group differences in the task of sequencing words to make a sentence. Conclusions: These results indicate that patients with PD do have IA, an action-sequence planning deficit. Further research is needed to better understand mechanisms, ecological implications, and potential treatments. Copyright © 2011 by Lippincott Williams & Wilkins.