In a process for producing self-sealing tires for vehicle wheels, a continuous sealing assembly, including a self-supporting thermoplastic film and a layer of polymeric sealing material, is wound from a reel holder on which is stocked, separated by a protective film associated with the layer of polymeric sealing material, cut to size and then wound around a forming drum. Winding the sealing assembly cut to size includes: feeding the sealing assembly cut to size onto a chute from top to bottom up to the forming drum; depositing a leading end of the sealing assembly cut to size on a radially outer surface of the forming drum; locking the leading end on the forming drum by means of a locking bar; setting the forming drum in rotation with the locking bar dragging the sealing assembly cut to size and winding it on the forming drum up to overlapping; and sealing a trailing end of the sealing assembly cut to size on the leading end.