A stereoscopic endoscope includes an imaging optical system including a diaphragm which adjusts light intensity and a pupil splitting polarizing element that has a pair of polarizers which are disposed to line up along a splitting line as a boundary a scope holder in which at least the pupil splitting polarizing element is disposed in an inner portion thereof and an imaging device on which light is incident via the imaging optical system. Light which is incident on the pupil splitting polarizing element is polarized by the pair of polarizers in order to generate a right eye image and a left eye image, respectively. A direction that is perpendicular to both the splitting line and an optical axis is a positioning direction. Positioning portions are provided to position the pupil splitting polarizing element in relation to a conjugate position of the diaphragm, or a proximity thereof, in the positioning direction.
