Disclosed is a stereo endoscope system comprising stereo endoscopes of varying working lengths, working diameters and directions of view. Each stereo endoscope comprises two identical optical systems where every pair of corresponding components is permanently couple in a sideways orientation. The system is capable of withstanding harsh conditions associated with medical equipment cleaning and sterilization, particularly, the high temperatures and pressures associated with autoclaving. Each of the corresponding components of the two identical optical systems is paired and moved relative to each other to adjust focus and then affixed to create a new singular optical component. The system includes a prism block that extends the distance between the optical axes on the stereo endoscope to the position of two video chips.