The invention relates to a brake system for motor vehicles, mainy comprising a piston-cylinder arrangement (2) which can be actuated by means of a brake pedal (1), a controllable pressure source (7) and brake pressure modulation valves (6a - 6d). In order to provide the piston-cylinder arrangement (2) which is easy to implement and axially short, the invention proposes that a piston (3) of the piston-cylinder arrangement (2) is directly guided in a housing (35) that accommodates further components of the brake system according to the invention.