G6PD deficiency is one of the most widespread genetic disorders in the world, affecting over 400 million people, mainly from the Mediterranean basin. Being an X-linked disease, it mainly affects boys, although girls can also be affected (de novo mutations). The WHO has classified the deficiency into 3 classes. Class 2 and 3 deficiencies are characterized by a risk of acute hemolytic shock due to oxidative stress.Outside the acute episode, management is based on preventive measures, avoiding drugs and foods that may precipitate an intravascular hemolysis crisis.