Several studies have indicated a link between adverse outcomes, fatigue, and sleep loss. We extended this work by adding the concept of clinical-decision self-efficacy (confidence, satisfaction, and decision regret) and used decision regret as the primary outcome variable. Critical care nurses who experience impairments due to fatigue, poor sleep, and inability to recover between shifts are more likely than not impaired nurses to report clinical-decision regret. Decision regret was most common among nurses who are male, work 12-hour shifts, and have lower levels of satisfaction with their clinical decisions. FINANCIAL DISCLOSURES This research was funded in part by Kirkhof College of Nursing, Grand Valley State University, and the American Association of Critical Care Nurses