An underwire brassiere comprising a pair of adjoining breast cups, each breast cup defining an underwire channel extending along a lower margin of the breast cup for disposition immediately beneath a wearer's breasts, and at least one supporting underwire shaped in conformity with the lower margins of the breast cups and extending within the channels thereof, each channel comprising a generally inelastic and dimensionally stable warp knitted textile fabric comprising a plurality of generally inelastic yarns interknitted with one another in stitches arranged in longitudinally extending fabric wales and transversely extending fabric courses, the yarns comprising a first set of yarns each warp knitted in a pattern of coursewise spaced stitches with extended underlaps therebetween for providing structural stability and elongation resistance coursewise of the fabric and a second set of yarns each warp knitted in a pattern of walewise aligned chain stitches for providing structural stability and elongation resistance walewise of the fabric, the chain stitches of the second yarns being canted in a coursewise inclination relative to the walewise alignment of the second yarns for providing the fabric with a predetermined degree of walewise elongation to promote conformation of the fabric to the shape of the underwire in fabrication of the brassiere.