The pelvic floor or pelvic diaphragm is composed of muscle fibers of the levator ani, the coccygeus muscle, and associated connective tissue which span the area underneath the pelvis. The pelvic diaphragm is a muscular partition formed by the levatores ani and coccygei, with which may be included the parietal pelvic fascia on their upper and lower aspects. The pelvic floor separates the pelvic cavity above from the perineal region (including perineum) below.
Some sources do not consider “pelvic floor” and “pelvic diaphragm” to be identical, with the “diaphragm” consisting of only the levator ani and coccygeus, while the “floor” also includes the perineal membrane and deep perineal pouch. However, other sources include the fascia as part of the diaphragm.In practice, the two terms are often used interchangeably.

Posteriorly, the pelvic floor extends into the anal triangle.

The pelvic floor has two hiatuses (gaps): Anteriorly urogenital hiatus through which urethraand vagina pass through and posteriorly rectal hiatus through which anal canal passes.