Prolonged bed rest is common in critically ill patients, and therapeutic positioning is important to prevent further complications and to improve patient outcomes. Nurses use therapeutic positioning to prevent complications of immobility. This article reviews therapeutic positions including stationary positions (supine, semirecumbent with head of bed elevation, lateral, and prone) and active repositioning (manual, continuous lateral rotation, and kinetic therapy). The physiological rationale and current evidence for each position are described. Applicable evidence-based practice guidelines are summarized. Special considerations for therapeutic positioning of critically ill obese and elderly patients are also discussed.