Objective: Recurrent implantation failure is defined as the absence of implantation, after two or three consecutive cycles of in-vitro fertilization (IVF), intracytoplasmic sperm injection or frozen embryo replacement. Human fetuin-A/alpha2-Heremans-Schmid-glycoprotein is a plasma protein secreted by the liver that modulates insulin action in adipocytes. Increased fetuin-A promotes adipocyte dysfunction which results in decreased adiponectin and increased fatty acids and inflammatory cytokines. Fatty acids and inflammatory cytokines were previously reported in implantation failure. Also, fetuin-A inhibits receptor tyrosine kinase activity in trophoblast growth factors which decrease trophoblast viability and invasion. In this study, we aimed to find the association between fetuin-A and implantation failure.