Abstract: A water jet surgical device comprises a fluid feed device, which is controllable by control signals from a control device, for delivering a fluid into a connecting line of a surgical instrument with an outlet nozzle. The fluid feed device includes at least one measuring device, which is configured such that following the connection of the surgical instrument to the fluid feed device, the measuring device generates measuring signals to represent a quantity of fluid delivered. The quantity of fluid delivered may be displayed on a display or recorded in a recording unit. This enables improved monitoring of surgical operations.