Abstract: A sheet-folding device having pairs of prefolding and pressure rollers (3, 4 and 8, 9, respectively) of identical diameters successively arranged for rotation in a machine frame (1). A first pressure roller (8) is stationarily mounted to machine frame (1) for rotation, whereas the first prefolding roller (3) is rotatably mounted on spring-urged support members (10) which are slidable normally to the folding direction (A). The second prefolding roller (4) is mounted for rotation on shaft (14), said shaft being supported in lever arms (15) pivotally mounted to machine frame (1). Connecting arms (21) are hinged to the shaft (14) to support the second pressure roller (9) for rotation on shaft (13).