Abstract: A friction device for rolling up curtains and the like includes a tubular roller (1), on which a curtain (1a) is wound. The roller (1) is rotatably carried by a support (10) and a threaded stem (2) is situated axially inside the roller (1) and carries, mounted thereon by a screw coupling, an operative body (3), likewise situated inside the roller (1). The operative body (3) translates axially with respect to the threaded stem (2) during motion of the curtain (1a) from a rolled up configuration (A) to a unrolled configuration (B). Elastic blocks (41, 51) push on the operating body (3) to produce a friction effect on the operating body and transmitted to roller (1) during curtain (1a) transition between the unrolled and rolled up configurations, thus allowing operation of the curtain in a substantially balanced way during rolling up and/or unrolling. Stop nuts (40, 50) are fastened to the threaded stem (2) for compressing the elastic blocks against surfaces of the operating body (3).