The delivery of supplemental oxygen is a critical part in the management of patients presenting with acute hypoxemia. While a number of delivery options are available, one of easiest and least invasive is the simple facemask or “Venturi” mask. Worldwide, these types of masks have been used for over 50 years. Developed initially as simple oxygen-delivery system, the face mask has evolved, acquiring more complexity and efficacy by the application of physical principles in an attempt to provide maximal patient benefit. The original Venturi mask was created by the British physician Earl James Moran Campbell. It was named after the Italian physicist Giovanni Battista Venturi who described the principal of increased velocity of a gas resulting in lower pressures, Campbell incorporated Venturi's principle into the oxygen delivery facemask. By using this principle, precise oxygen delivery occurs, thus, representing the standard of supplemental oxygen facemasks today.