Abstract: A fish is scaled, and its internal organs removed, by continuously advancing the fish along a treatment path while simultaneously exposing the fish body to high-pressure water jets. During treatment the fish is positioned vertically, with the belly downwards. The forces required for holding and transporting the fish are applied laterally to the upper part of the fish body, which is harder, without touching the belly area, which is soft and therefore is left free. The descaled fish proceeds to a position for cutting the belly area and removing the internal organs. The treatment is carried out in the same devices efficiently and without deterioration of the gustatory properties.