: 158 non-pregnant women with recurrent implantation failures after IVF/ET procedures were tested for peripheral blood autoimmune profile. The control group consisted of 76 patients after first successful IVF procedure and pregnancy outcome. The objective of this study was to investigate different autoantibodies peripheral blood profile after excluding anatomical, endocrinological, endometrial and genetic disorders and to estimate the risk of implantation failures. The study's including criteria were 1.indications for IVF/ET determined by male factor and unexplained infertility 2. absence of implantation after two consecutive cycles of IVF, ICSI or frozen embryo replacement cycles. The presence of ANA in the sera increased the risk of RIF after ET/IVF procedures, especially in older patients. Patients with RIF have a higher frequency of the presence of autoantibodies ACA IgG, IgM and anti-β2GP I IgG in the sera than in patients with successful pregnancies after IVF/ET procedures.