Retinoids are useful pharmacological agents in therapy and prevention of cancer. All-trans retinoic acid (ATRA) is applied in chemoprevention and differentiation therapy of some cancers with particularly impressive results in the management of acute promyelocytic leukemia (APL). ATRA plays a major role in regulating growth and differentiation of a wide variety of normal and malignant cell types. ATRA mediates these effects by regulating gene transcription. Nuclear retinoic acid receptors (RARs) are considered to be the mediators of most of the effects of ATRA on gene expression. We present a current state of knowledge on the effects of ATRA on cell growth and differentiation as well as describe RARs and their role in the cellular mechanism of ATRA action. A particular attention was paid to the effects of ATRA on proliferation and differentiation of cancer cells.