The process for manufacturing a complete garment on a two needle bed flat knitting machine, which operates with latch needles, which process consist of the fact that at least at the beginning of the manufacture of the garment, half of the needles of the front needle bed are put to work with the empty (idle) needles of the rear needle bed and viceversa in order to perform, during the steps of forming of the tubular portions of said garment, also an operation of narrowing of the knitted product in pre-established areas of said tubular portions.