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The perineum is the region situated inferior to the pelvic diaphragm, which comprises the levator ani and coccygeus muscles, and is bounded by the pelvic outlet or inferior pelvic aperture. The perineum approximates a diamond-shaped area formed anterolaterally by the ischiopubic rami and posterolaterally by the sacrotuberous ligaments. An imaginary line joining the ischial tuberosities separates the perineum into anterior urogenital and posterior anal triangles. The perineal body lies centrally along this line, serving as the point of convergence between both triangles. A dense fascial layer, the perineal membrane—historically referred to as the "inferior fascia of the urogenital diaphragm"—further subdivides the urogenital triangle into the superficial and deep perineal spaces. The superficial perineal space is positioned inferior to the perineal membrane, while the deep perineal space lies superior to this structure. The deep perineal space (pouch) is bounded inferiorly by the perineal membrane, superiorly by the inferior fascia of the pelvic diaphragm, and laterally by the inferior portion of the obturator fascia, which overlies the obturator internus muscle. In both sexes, this space contains the urethra, the muscles of the external urethral sphincter complex, and the neurovascular structures supplying the external genitalia. In male individuals, the deep perineal space also contains the bulbourethral glands (see Image. Male Pelvic Floor Anatomy). In female individuals, this region includes the vagina (see Image. Female Perineum). Clinically, the deep perineal space serves as a key landmark for urethral and pelvic floor surgery. Familiarity with the muscular and fascial architecture of this region allows clinicians to anticipate the course of neurovascular structures and localize sites of fluid extravasation or trauma. A deep understanding of the anatomy of the deep perineal space helps clinicians prevent complications and refine operative techniques.