Background: Patient self-administration of medications for analgesia and procedural sedation is common. However, it is not known whether mechanically ventilated ICU patients can self-administer their own sedation to manage symptoms. Methods: This descriptive pilot study examined the safety, adequacy, and satisfaction of patient-controlled sedation (PCS) with a convenience sample of critically ill, mechanically ventilated patients (N = 17) in the ICUs at University of Minnesota Medical Center, Fairview, Minneapolis, Minnesota. Dexmedetomidine was administered via a patient-demand infusion pump system for a maximum of 24 h. Pumps were programmed with basal infusion plus patient-triggered boluses; nurses adjusted the basal infusion based on a dosing algorithm. Data were collected on sedation adequacy, additional dosing of analgesics and sedatives, hemodynamic parameters, safety of PCS, patient satisfaction with PCS, and nurse satisfaction with PCS. Results: Although a majority of the hemodynamic values were within the established safety parameters for the study, 25% of patients experienced mild adverse physiologic effects. Furthermore, despite patients' perception of sedation adequacy with PCS, 70% received supplemental opiates or benzodiazepine medications while participating in the study. Patients rated dexmedetomidine PCS favorably for self-management of anxiety, level of relaxation obtained, and comfort in self-administering sedation. Nurses also were generally satisfied with PCS as a method of sedation, dexmedetomidine as the sedative, and patient response to the sedation. Conclusions: PCS warrants further investigation as a means to promote comfort in mechanically ventilated critically ill patients.