Pelvic floor disorders are a common clinical problem. Clinical evaluation frequently underestimates the extent of the disease. Fluoroscopic colpocystodefecography (CCD) is an established tool for diagnosing disorders of the rectum and recto- anal junction. It is however less performant when it comes to evaluate the complex pelvic floor mechanism in all its aspects. MR defecography allows to evaluate all the compartments of the pelvis without being invasive. This article describes the clinical setting, the MR technique and provides guidelines for interpretation of a MR defecography study.