A roll-up video-projection screen (1) has a transverse upper casing (2) enclosing a horizontal rotating drum (11) around which rolls up and unrolls a projection fabric (10) provided at the bottom part with a weighting and tensioning element (30). The projection fabric (12) has a front projection face (12). The screen (1) includes a mechanical assembly (20) imposing, when the fabric (10) is unrolled, a transverse curvature to the front projection face (12). The imposed curvature of the front face (12) of the fabric (10) also exists in the unrolled position of use of the screen (1).