The complicated process of invasion and metastasis consists of a long series of sequential and interrelated steps. The outcome of the process is dependent on both: the tumour cells and the properties of tissue microenvironments. Many investigators are interested in the influence of extracellular matrix components on that process. Especially matrix metalloproteinases (MMPs)--family of zinc-dependent enzymes, which take part in the coordination of extracellular matrix synthesis and breakdown seems to play crucial role in this process. A positive correlation between different type of MMPs and specific tumors has been demonstrated in many studies. In this article we summarize the current views on the role of MMPs in cancer invasion and metastasis.