The invention is a brassiere accessory for improving posture, and more specifically, to a brassiere accessory that couples to and between shoulder straps at the posterior portion of a brassiere. The brassiere accessory rests against the back of a user providing a supportive tension that prevents excessive kyphosis (curvature) of the thoracic spine (upper back) and straightens the back of the user so that the user's posture is improved.