Method for regulation of a single-valve CO2 refrigerating apparatus including: an operation A of detecting, over time, the value of a primary parameter and the value of a secondary parameter, wherein said primary parameter is chosen from said high pressure HP and said superheat temperature Tsh, wherein said secondary parameter is said superheat temperature Tsh if said primary parameter is said high pressure HP or is said high pressure HP if said primary parameter is said superheat temperature Tsh; a primary regulation operation B, which involves regulation of said expansion valve (13) so that the value of said primary parameter tends towards a set-point value; an operation C of estimating an optimal value Vo for said secondary parameter; and a secondary regulation operation D which involves varying said set-point value from an optimal set-point value or from a current value if the value of said secondary parameter does not fall within a predefined tolerance range.