We study the impact of decoherence on B meson systems with specific emphasis on B s . For consistency we also study the B d mesons based on the most recent data. We find that the B d mesons are 34σ away from total decoherence, while the B s mesons are seen to be upto 31σ away from total decoherence. Thus, our results prove, with experimental verity, that neutral meson systems are free from decoherence effects. Therefore, this provides a very useful laboratory for testing the foundations of quantum mechanics.