A procedure for mounting of a hub bearing assembly having a rotatable hub, and a bearing unit having a stationary radially outer ring, and two bodies rolling crowns disposed between the radially outer ring and the hub. The assembly process involves the following steps: a) pressing-fit a first seal on the hub, b) mounting an axially external cage and the axially outside rolling bodies, in correspondence with a track of the axially outer hub, c) the radially outer ring assembly and inclination of the same outer ring of a predetermined angle with respect to the hub, d) mounting of the axially interior rolling bodies in correspondence with a track of the axially inner hub, and the radially outer ring alignment to the hub, f) snap insertion of the axially internal cage on rolling bodies and g) the pressing-fit a second axially internal sealing means on its seat.