Endoscopes can be diagnostic or operative. A diagnostic endoscope is limited to only viewing a hollow space or organ, and an operative endoscope is equipped with channels to irrigate, suction and insert instruments or other accessory items to perform a surgical procedure. An endoscope may be inserted into the human body by using a natural orifice (anus, cervix, mouth, and urethra) or through a tiny surgical incision. There are three basic types of endoscopes: rigid, semi-rigid, and flexible which is determined by the materials used to make the endoscope. A rigid and semi-rigid endoscope has a stainless steel body and glass rod lenses or fiber optic lenses that allows the surgeon to visualize the structure or organ. The rigid endoscope ‘s visualization is achieved by the degree of the lens and not the flexibility of the scope. A flexible endoscope has a flexible, plastic insertion tube and a distal tip that bends in a variety of degrees. The flexible endoscope allows the physician to access and view more areas of the body than a rigid endoscope. The rigid endoscope comes in a variety of view angles: 0 degree for forward viewing, 30 and 45 degree for forward oblique views, 70 degree for lateral views and 120 degrees for retrograde views. The flexible endoscope has one lens type, but can be used to view forward, forward oblique, lateral and retrograde by flexing the bending distal tip. This continuing education activity will describe the structural differences between rigid and flexible endoscopes as well as surgical uses for both types of endoscopes. Additionally, the steps for cleaning and the Spaulding Classification System will be discussed as a basis for determining the appropriate sterilization method for flexible and rigid endoscopes.