Objective: Delirium is a frequent syndrome in elderly hospital patients. Symptoms typically show a fluctuating course during the day, with patients exhibiting disturbances of their sleep-wake rhythm. Delirium is frequently underdiagnosed, especially the so-called hypoactive subtype. Devices measuring 24-hr motor patterns could contribute to the recognition of delirium. The purpose of this paper is two-fold. First, the results of a pilot study are presented, in which 24-hr motor patterns of delirious patients are measured with a wrist-actigraph. Second, studies reporting 24-hr motor patterns in delirious patients are systematically reviewed. Methods: The pilot study included 9 patients, 65 years or older, with a hip fracture in need of surgical repair. For the review, MEDLINE and Embase were searched for studies on motor activity assessment in delirious patients. Results: In the pilot study, the 24-hr activity rhythm was severely disturbed during delirium, and most actigraphic sleep parameter estimates indicated significantly worse sleep during delirious nights. The systematic search resulted in 10 papers. In 3 papers, the sleep-wake rhythm of delirious patients was significantly different from that of nondelirious patients. In 5 papers, delirious patients could be classified into delirium subtypes. In the 2 remaining papers, 24-hr motor patterns of delirium subtypes were not significantly different. Conclusion: Activity patterns revealed differences between delirious and nondelirious patients and between the different subtypes, even in small samples of patients. Future studies, with preferably larger sample sizes, should confirm the potential of activity pattern measuring devices in the early detection of delirium. © 2011 Mary Ann Liebert, Inc.