Recent studies have shown that different populations of trophoblastic cells of first-trimester human placenta express human chorionic gonadotropin/luteinizing hormone (hCG/LH) receptors. Among these trophoblastic cells, extravillous cytotrophoblasts (CTBs) not only express hCG/LH receptors but also present an invasive phenotype. CTB invasion is instrumental in blastocyst implantation and later in placentation and is tightly regulated in both time and space. This article describes some of the regulators of CTB invasion and summarizes and discusses the potential autocrine/paracrine role of hCG in trophoblast invasion.