A method for preparing shellfish, especially lobsters and crawfish, characterized by the following successive stages: the shellfish is frozen or deep frozen at a temperature of 25 DEG C; the shellfish is cut into two lengthwise; the viscera are extracted in a solid state by perforation in order to separate them from the edible part, whereby care is taken to ensure that the temperature of the shellfish does not rise above 18 DEG C; the viscera which are separated from the edible part are externally removed; and the eviscerated shellfish is stored in a refrigerating chamber at a temperature of - 18 to 25 DEG C.