The ischioanal fossa (formerly called ischiorectal fossa) is the fat-filled wedge-shaped space located lateral to the anal canal and inferior to the pelvic diaphragm.

It is somewhat prismatic in shape, with its base directed to the surface of the perineum and its apex at the line of meeting of the obturator and anal fasciae.

It has the following boundaries:[1] INFERIOR:* skin The contents include: This article incorporates text in the public domain from page 425 of the 20th edition of Gray's Anatomy (1918)