Knowledge of the anatomy and function of the lower urinary tract is essential in the management of the patient with urinary incontinence. The lower urinary tract is comprised of the bladder, which is a storage organ, and the urethra, which is a conduit for the expulsion of urine. There is also a bladder neck (internal) and rhabdosphincter (external) urethral sphincter mechanism which maintain continence. The bladder has two functions: urinary storage and expulsion (voiding). Both storage and voiding require intact neurological pathways involving both autonomic and somatic pathways including interactions with the sphincteric mechanisms and the pelvic floor. This chapter reviews the anatomy and physiology of the lower urinary tract including the pathophysiology of urinary incontinence.