Method for packing groups of products or products of prismatic shape with rectangular or square base, which from a feed or grouping unit are then moved towards a first folding spindle so as to be delivered therefrom wrapped in the shape of a “U” rotated through 90° and open at the back, by a packing sheet which is previously placed in front of the spindle with vertical positioning, characterized in that the product with the packing sheet delivered from the spindle are picked up directly and fed in phase between the parallel and horizontal motorized conveyors of a tilting drum positioned inside which longitudinally, edgewise and parallel with each other, are folding devices which guide the product with the packing laterally and fold on the lateral faces of the product the first flaps with vertical folding, projecting laterally and anterior in the feed direction of the packing.