Background: the presence of antithyroid antibodies (ATA) are frequently encountered in general population and approximately 1/5 of childbearing age women are positive for the antithyroid peroxidase antibody (TPO-Ab) or antithyroglobulin antibody (TG-Ab). Autoimmune thyroid diseases are rather frequent in women in the childbearing age, affecting 5-20% of them. They are characterized by the presence of antithyroglobulin and antithyroperoxidase antibodies, grouped under the definition of ATA. ATA are often detected in subjects complaining of hypo- or hyperthyroidism, but are no rarely found in patients without any sign of thyroid dysfunction. Aim of the Work: to investigate the impact of antithyroid antibodies on pregnancy outcome in cases of one or two failure of Intracytoplasmic Sperm Injection (ICSI) cycle. Patients and Methods: the present study is a prospective study. This study was conducted at Ahmed Oraby IVF center (private center), and was approved by the Medical Ethical Committee of Al-Azhar University. Informed consent was obtained from every patient according to Hospital Ethics Committee. Age of patients, diseases status and previous treatments were recorded. This study was done on 50 patients complaining of infertility with history of one or two failure of ICSI cycle and patients divided into two groups, in the ATA positive group, 25 women were positive for TG-Ab and/or TPO-Ab, 25 women negative for TG-Ab and/or TPO-Ab served as controls. All patients did not receive any adjuvant treatment, such as glucocorticoids, anticoagulants, or other adjuvants. Patients with other autoimmune diseases, or positive for anticardiolipin antibody, antinuclear antibody, lupus anticoagulant, or rheumatoid factor were excluded from this study. Results: there were no significant differences in age, BMI, basal LH, FSH levels, cause of infertility and duration of infertility between two main groups. No significant differences in terms of the days of ovarian stimulation, estradiol level, total gonadotropins dose, number of oocytes retrieved, available embryos and blactocysts number neither of embryos transferred nor in rates of fertilization, implantation and clinical pregnancy between two main groups were found. The only statistically significant among the ATA positive group increase the abortion rate was found p value 0.02.    Conclusion: patients with anti-TPO antibodies showed no significant differences in fertilization, implantation, pregnancy rates, live birth rates but higher risk for miscarriage following intracytoplasmatic sperm injection-ICSI and embryo transfer when compared with those negative for anti-thyroid antibodies.