A magnetorheological braking device with a fixed holder and a first and second braking component. One of the braking components is connected to the holder and does not rotate relative thereto. The two braking components are continuously rotatable relative to one another. The first braking component extends axially, and the second braking component has a hollow shell part extending around the first braking component. A peripheral gap, filled with a magnetorheological medium, is formed between the first and second braking component. The first braking component has an electric coil and a magnetically conductive core extending axially. Magnetic field concentrators, on the core and/or the shell part, protrude into the gap, creating variable gap height. The electric coil is wound around a section of the core. A magnetic field of the electric coil runs through the core, magnetic field concentrators, and the gap into a wall of the shell part.