Failure of the embryo to implant successfully into the endometrium is one of the major causes of infertility. Many causes of infertility, such as sperm dysfunction and certain disorders of the fallopian tube or ovary, can be identified and either treated or bypassed by in vitro fertilisation (IVF). There are few models of human embryo implantation that have been exploited to dissect the implantation process and from which information about the function of specific molecules involved has been obtained. Solid-phase assays have been used previously to determine the function and signalling properties of extracellular matrix (ECM) components in the adhesion and trophoblast outgrowth of mouse blastocysts. The interaction of the blastocyst with various cellular components of the endometrium can be investigated in co-cultures of isolated cells and peri-implantation blastocysts. Model systems for the study of complex processes such as implantation of the human embryo can involve varying degrees of complexity.