A pressure-medium-actuated brake cylinder of a rail vehicle has a housing, a translationally movable brake piston rod extending through a bore in a housing base, a guide ring which is received in the bore, encloses the brake piston rod and is intended for guiding the brake piston rod in the bore, and at least one sealing ring which is received in the bore, encloses the brake piston rod and is intended for sealing an interior of the housing with respect to a space outside the housing, wherein the guide ring and the at least one sealing ring are designed as a guide and sealing ring combined to form a structural unit.