A posture support garment includes a shirt 10 of stretchable material adapted to be tight fitting on the upper body of a user when worn. In order to improve posture a series of panels 11,12 are sewn into the shirt to form a portion of reduced stretchability i.e. reduced elasticity, in at least one direction compared to the stretchable shirt. In the preferred form the restrictive portion is a v-shaped band 12 that extends from a spine area of the rear of the shirt toward and over the shoulders 11. This construction encourages the users posture to be pulled back, away from a slumped or hunched position.