A method for the production of a packing case from a one-piece blank, comprising a band of at least four main panels connected together by parallel fold lines, and furnished with two series of flaps situated on either side, for respectively forming at least partly the bottom and the top of the case. The band comprises a precut transverse line over the main panels to divide the blank into a first and a second half-blank. The half-blanks are separated, the first is placed in a transfer channel, the second is held in a plane higher than that of the transfer channel, the first is transferred to a mandrel while applying adhesive, and the first is wrapped around the mandrel. The transfer channel allows the second to be lowered to the channel, transferred to the mandrel, and wrapped around the first half-blank before folding the flaps.