The invention refers to a brake for a trolley that can brake rotation of a trolley wheel only in one direction. The brake (1) comprises a support connectable with a frame of the trolley, a first axle (3) connected with another end of the support and peripherally provided with three indents (3a), a pivotal first handle (4) with a detent (5), wherein the first handle (4) on the first axle (3) can assume three positions defined by the three indents (3a), a pin (6) connected with the first handle (4) and arranged parallel to the first axle (3), an eccentric ring (7) with a recess (7b), through which the pin (6) projects, wherein the eccentric ring (7) is pivotally mounted on the first axle (3) and can engage with the outer periphery of the pulley wheel, a tension spring (8) connecting the inner periphery of the eccentric ring (7) and the pin (6), and a stop element (9) projecting from the first axle (3), which can lean against the inner periphery of the eccentric ring (7). The brake enables unidirectional braking of a trolley either in forward movement or in rearward movement.
