A printing unit consists of at least two printing groups, which are placed vertically above each other, in a printing machine. Each of the printing groups includes a printing cylinder, an inking unit with at least one inking roller, a dampening unit with several dampening rollers arranged in a line, and a transfer cylinder that cooperates with the printing cylinder. The inking cylinder and the dampening roller, in an operational state in which they are adjacent the printing cylinder, form an obtuse opening angle with the printing cylinder. The rollers of the dampening unit are arranged with at least the first and last rollers in the roller train arranged inside an acute angle depending from the transfer cylinder. A horizontal line extending from the transfer cylinder defines an opening angle of less than 45.degree. with the rollers of the dampening unit. A printing forme is fed to the printing cylinder through an obtuse angle between the dampening roller and the inking roller.