Optical information processing is an essential part of contemporary photonics, and it remains a challenge for researchers around the world. The presented work investigates numerically a maximum number of all-optical logic gates in a cascade. The functionality of the all-optical logic gate is based on the injection locking technique with semiconductor lasers. The possibility of cascading a sequence of AND and OR gates, providing a high-quality final signal, is demonstrated for a planar vertical-cavity surface-emitting laser using the traditional Lang–Kobayashi model. It is shown that the maximum number of cascaded gates is limited to three for repetition rates less than 1 Gbit/s.