A process for packing products based on portions of fish in the solid form comprises at least the step of introducing (120) one or more portions of raw fish in the solid form in the frozen state into an at least partially flexible packaging the step of performing mechanical vacuum (130) inside the packaging filled in with one or more portions of fish in the solid form in the frozen state the step of sealing (140) the package to form a sealed package comprising one or more portions of fish in the solid form still in the frozen state the heat sterilization step (150) in an autoclave of the sealed package comprising one or more portions of fish in the solid form still in the frozen state, in which the portions of fish remain in the frozen state for all the packing process until the start up of the sterilization step (150), said sterilization step carrying out the cooking of the portions of fish in the solid form still in the frozen state. A package of one or more portions of fish in the solid form (10), cooked during heat sterilization in an autoclave, comprises the portions of fish in the solid form (10) vacuum contained in an at least partially flexible packaging, such portions of fish in the solid form (10) having muscle bundles (12) substantially intact and separable to each other.
