The relationship between thyroid state and female fertility is an area of particular interest for both clinicians and researchers worldwide. This is partially due to the increasing prevalence of infertility and to the understanding of its complex and multifactorial aetiology. Studies conducted in variable forms of female infertility (e.g., recurrent miscarriages or polycystic ovarian syndrome) together with the worldwide rising use of assisted reproduction technologies (ART) contributed the uncovering of the potential role of thyroid conditions in relation to ovarian function and fertility. However, as the title of this short review suggests, several aspects are yet to be elucidated and several questions are still awaiting an answer. This short review is mainly focusing on the distinct roles of thyroid dysfunction and thyroid autoimmunity in infertile women undergoing ART procedures.