Sickle cell disease is a common but often poorly understood by chest physicians. The acute chest syndrome represents its main respiratory complication. STATE OF ART: Sickle cell disease is an autosomal recessive disorder inducing, in certain circumstances, sickling of red cells. Natives from western or central Africa and from the Caribbean islands are mainly affected. Acute chest syndrome is defined by the association of chest pain or fever and recent radiographic infiltrates, in patients suffering from sickle cell disease. Determination of etiology, infection, fat embolism or hypoventilation, is difficult, as a self-perpetuating vicious circle is ongoing. Support, largely undervalued, is based on etiological treatment and measures to avoid worsening linked to complications, especially microcirculatory disease. CONCLUSIONS: Acute chest syndrome is a severe respiratory complication of sickle cell disease. Therapeutic measures are simple but undervalued.