A mobile C-arm system contains a main unit having a relocation apparatus for moving the main unit in a horizontal movement direction and a C-arm which is movable at least in the orbital and angular movement direction, a data processing unit having a memory for storing programs which are executed during operation, and a control and display system, connected to the main unit with operating and display elements. A plurality of sensors are provided for capturing at least part of the immediate environment of the C-arm. A control system is present, which is configured to warn against an obstacle in the intended or actual movement direction on the basis of the environment captured by at least one sensor, in dependence on an intended or actual movement of the main unit and/or at least part of the main unit in a movement direction.
