Matrix metalloproteinases (MMPs) are the main mediators of extracellular matrix degradation. This confers an important role to these enzymes in the invasion of the trophoblast cells where their expression are spatiotemporally regulated. The regulation of MMPs activity is complex and is established at different levels. Their expressions depend on various cis-elements in their gene promoter, and are induced or repressed by various soluble factors. After expression and secretion, the proMMPs must be activated through an activation network. Then, the enzyme activity is regulated by inhibition or stabilization. In this review, we shall focus on the expression, the role in invasion and the regulation of MMPs in the human placenta.