There is described a sheet inspection system for a sheet-fed recto-verso printing press of the type comprising two printing cylinders (10, 20) for carrying out simultaneous recto-verso printing of the sheets, said sheet inspection system comprising at least a first inspection device (100) for taking an image of a first side of the printed sheets. The first inspection device (100) comprises a first line image sensor (110) for performing line-scanning image acquisition of the first side of the printed sheets, and the first inspection device (100) is disposed in such a way that the first line image sensor visually acquires an image of a printed sheet while the said printed sheet is still adhering onto the surface of a first one (10) of the two printing cylinders (10, 20) of the printing press and immediately before the said printed sheet is transferred to a chain gripper system (5) of the printing press. Also described is a printing press equipped with the inspection system.