Abstract: A ladies' undergarment with a molded upper part, in particular a brassiere has two side parts which include cups, are joined together in the front central area between the cups, have a back fastener at the back ends and are provided with shoudler straps. Each side part includes a blank which covers their entire surfaces and is of a textile material which is composed at least in part of thermoplastically fusible fibres. Reinforcement parts are bonded to the blank parts at least along their outer edges. The reinforcement parts are also of a textile material which is composed at least in part of thermoplastically fusible fibres. The side parts are joined together in the front central area by a thermally produced weld. The parts of the back fastener as well as the shoulder straps are indirectly or directly joined to the side parts by thermally produced welds.