Calculus, whether primary or secondary, in a diverticulum of the female urethra is a condition that has received very scant mention in the literature. The rarity of calculus in this location is due to several quite obvious reasons, the chief one being that vesical calculus per se is comparatively uncommon in women and that when it does occur a stone, even of considerable size, will usually pass naturally from the bladder. This is possible because the female urethra is so short, straight and easily dilatable, as emphasized by Stevens.1 However, if a diverticulum is present in the urethra a migratory calculus may easily lodge within it. Much less commonly a stone forms in one of these pouches, and it is this type of case that we report. The urethral diverticulum in the female consists of a pouch or cavity situated in the urethrovaginal septum, usually about the middle third,