Cutis laxa is an inherited or acquired disease characterized by redundant, sagging and inelastic skin. In inherited cutis laxa an abnormal synthesis of extracellular matrix proteins occurs due to genetic defects coding for diverse extracellular matrix components. Recently, different inborn errors of metabolism have been found to be associated with cutis laxa as well. In some of these metabolic conditions the pathomechanism of cutis laxa remains unknown. Cutis laxa can be inherited in an autosomal dominant, autosomal recessive and X-linked recessive inheritance pattern. Besides the skin abnormalities, in most inherited forms multiple organ systems are involved, leading to a severe, in some forms even lethal, multisystem disorder. To date no effective treatment is available for cutis laxa. This chapter focuses on inherited forms of cutis laxa, offering a practical guideline for clinicians, biochemist and geneticist to diagnose and differentiate between the different forms of cutis laxa, and providing a concise theoretical reference.