Serious adverse events are fortunately quite rare for procedural sedation. Current physiologic monitoring recommendations are therefore either based on "softer" outcomes, such as transient hypoxemia, or on expert opinion. Pulse oximetry and supplemental oxygen are recommended for the reduction of hypoxemia. Outcomes-based data for extended monitoring are just starting to emerge, and one of these technologies may become a recommended component of patient monitoring. With data on more than 150,000 patients published in the literature, propofol is the most studied sedative agent for gastrointestinal endoscopy. In this author's opinion, its safety and efficacy have been established.