A device (10-10′), (11-11′) for the localized heating of parts of metal pipes (12) connected to each other and of parts of primary plastic coating (16′-18′) of the same pipes, all to be coated with protective material, comprises a spiral-wise development winding consisting of one or more coils (20) and of annular means that are arranged within and coaxially to said coil (20), at the parts of primary plastic coating (16′-18′), and that surround each one of said pipes (12) for heating by induction a zone (14) without primary plastic coating and for indirectly heating, by irradiation, end portions of the same provided with plastic coating (16′-18′) contiguous to said zone (14).