A method and unit for feeding products to a group-forming unit forming groups of products, each defined by a given number of products; an orderly succession of products is fed in a first direction by a first conveyor; the products are transferred from the first conveyor to a second conveyor by a first transfer device; an orderly succession of products is fed in a second direction by the second conveyor; the products are transferred from the second conveyor to a third conveyor by a second transfer device; an orderly succession of products is fed by the third conveyor in a third direction parallel to the second direction; and, when a vacancy is detected on the first transfer device, the second conveyor is stopped, and, at the same time, the second transfer device is moved towards the first transfer device in the opposite direction to the second direction.