Method for building tyres for vehicle wheels, comprising: - moving a plurality of building drums along a closed first-stage path, - moving a plurality of carcass sleeves being processed along an open first-stage path, wherein along a first stage operating section in common between said closed first-stage path and said open first-stage path each carcass sleeve being processed of said plurality of carcass sleeves being processed is built on a respective building drum of said plurality of building drums, said open first-stage path ending at a gripping ring arranged in a fixed reference position, - moving a plurality of auxiliary drums along a closed second-stage path, and characterised by - moving a plurality of outer sleeves being processed along an open second-stage path, wherein along a second stage operating section in common between said closed second-stage path and said open second-stage path each outer sleeve being processed of said plurality of outer sleeves being processed is built and moved on a respective auxiliary drum of said plurality of auxiliary drums, said open second-stage path ending at said gripping ring, - at the end of the second stage operating section, separating from the respective auxiliary drum a first outer sleeve being processed of said plurality of outer sleeves being processed and holding said first outer sleeve being processed by means of said gripping ring, - at the end of the open first-stage path, arranging a first carcass sleeve being processed of said plurality of carcass sleeves being processed in a coaxial and radially inner position with respect to the first outer sleeve being processed held by said gripping ring, - shaping, inside the gripping ring, said first carcass sleeve being processed, assembling it with said first outer sleeve being processed to obtain a first green tyre being processed. - moving a plurality of building drums along a closed first-stage path, - moving a plurality of carcass sleeves being processed along an open first-stage path, wherein along a first stage operating section in common between said closed first-stage path and said open first-stage path each carcass sleeve being processed of said plurality of carcass sleeves being processed is built on a respective building drum of said plurality of building drums, said open first-stage path ending at a gripping ring arranged in a fixed reference position, - moving a plurality of auxiliary drums along a closed second-stage path, and characterised by - moving a plurality of outer sleeves being processed along an open second-stage path, wherein along a second stage operating section in common between said closed second-stage path and said open second-stage path each outer sleeve being processed of said plurality of outer sleeves being processed is built and moved on a respective auxiliary drum of said plurality of auxiliary drums, said open second-stage path ending at said gripping ring, - at the end of the second stage operating section, separating from the respective auxiliary drum a first outer sleeve being processed of said plurality of outer sleeves being processed and holding said first outer sleeve being processed by means of said gripping ring, - at the end of the open first-stage path, arranging a first carcass sleeve being processed of said plurality of carcass sleeves being processed in a coaxial and radially inner position with respect to the first outer sleeve being processed held by said gripping ring, - shaping, inside the gripping ring, said first carcass sleeve being processed, assembling it with said first outer sleeve being processed to obtain a first green tyre being processed.