Implantation failure is the most frequent cause of lack of pregnancy after in vitro fertilization (IVF) and embryo transfer (ET). Successful implantation requires trophoblastic growth into the endometrium to stimulate its own blood supply. The p53 tumor suppressor gene has been shown to regulate cell growth and induce angiogenesis. We, therefore, investigated the prevalence of p53 codon 72 polymorphism among women with history of recurrent implantation failure to determine whether this polymorphism may serve as a risk factor for implantation failure.