Implantation represents the remarkable synchronization between the development of the embryo and the differentiation of the endometrium. It depends on uterine-dependent and embryo-specific events, which are critically and sequentially coordinated. A plethora of molecules have been identified which play major roles before and after embryo implantation. In recent years HomeoboxA10 (HOXA10) has emerged as one of the most promising candidates which regulate the events occurring in the maternal compartment for successful establishment of pregnancy. HOXA10 is a transcription factor that is crucial for development and patterning of the uterus during embryogenesis. In the adult endometrium, HOXA10 is expressed in a menstrual cycle dependent manner and it is regulated by ovarian steroid hormones and embryonic signals, HOXA10 is required for uterine receptivity and implantation, and is a key regulator of decidualization. In the decidua, HOXA10 is involved in regulation of cell cycle and local immunomodulation. The present review summarizes the events that are regulated by HOXA10 in embryo implantation and decidualization.