In a system for the control of the quality of a laser cut or perforation, comprising means to focus a laser beam onto a cut or perforation zone, photodiode sensor means to detect the radiation emitted by the cut or perforation zone, and a control and processing electronic unit to process the signals emitted by said sensor means an optical filter is provided that is associated with said photodiode sensor means to select an optical band around 620 nm. The signal coming from said sensor means is acquired with a frequency comprised between 10 and 60 kHz and filtered with a band-pass filter between 7 and 16 kHz. In this way the control of the quality of the cut or perforation can be carried out on the basis of the sole signal thus processed, without the need of a comparison with the predetermined reference signal corresponding to a good quality cut or perforation.