For many researchers it is still difficult to accept that beneficial effects can be obtained in several disease states with the simplest amino acid, glycine. However, evidence is mounting in favour of this idea. It is now clear that dietary glycine protects against shock caused either by blood loss or endotoxin, reduces alcohol levels in the stomach and improves recovery from alcoholic hepatitis, diminishes liver injury caused by hepatotoxic drugs and blocks programmed cell death and reduces the nephrotoxicity caused by the drug cyclosporin A in the kidney, preventing hypoxia and free radical formation. It could be also useful in other inflammatory diseases since it diminishes cytokines production. We review some of the beneficial effects of glycine and their responsible mechanism, which could led to advice its use in the therapy of different diseases.