Systemic retinoids are drugs specifically employed in dermatology, with only isolated indications in other specialties. Nevertheless, they have effects on different organs different from skin, and dermatologists should be aware of these effects. In this chapter four drugs are reviewed: isotretinoin, acitretin, alitretinoin and bexarotene. There is a wide spectrum of conditions responsive to systemic retinoids: acne, psoriasis, eczema, cutaneous lymphoma… etc. and they are important instruments in their therapy, once adverse effects have been controlled. An individualized assessment has been performed, mainly on the indications and adverse events, due to the differences among them.