The invention relates to an automated system (1) for preparing parcels (100) of products, comprising: a storage assembly (2) housing product containers (7); a pick station (11); a main conveyor (12) which conveys the product container (7) between the inlet/outlet of the storage assembly (2) and the pick station (11); and a central management computer system (13) which manages the product order list associated with each parcel, said main conveyor (12) including means for arranging the containers (7) according to the order list, which means, in turn, comprise a first conveyor belt section (14), a second conveyor belt section (17) adjacent to the pick station (11) and a buffer zone between the outlet of the storage assembly (2) and the first belt section (14). The containers (7) are moved between the belt sections (14, 17) by transfer members in transfer zones (18, 181).