The invention relates to a knitted bra (10), comprising at least a first knitted cup (12a) and a second knitted cup (12b) which are transversely aligned and each have an overall hemispheric shape, each cup (12a, 12b) comprising a first elastically extensible knitted peripheral portion for supporting the chest, a stiffener (20) portion which extends at least partially under each cup (12a, 12b), and a strap (14) for attaching the back of the bra (10), characterized in that the stiffener (20) forms an underwiring strip which at least partially surrounds the first peripheral supporting portion (30a, 30b) of each cup (12a, 12b), and in that the stiffener (20) is knitted in a first type of stitch designed for replacing an added underwiring.