A method and device for quality controlling packets of cigarettes, whereby, as a packet is fed, in use, through a quality control station, an optical detecting unit acquires data relative to given portions of the packet, which portions are coated with material optically detectable at wavelengths outside the visible range; the data detected by the optical detecting unit is compared with reference data, and the outcome of the comparison is used to determine acceptance or rejection of the packet; in this way, the condition of the packet can be determined regardless of the graphics on the packet.