The incidence of having a single ovary is quite common in infertile patients and can reach up to 17% of women with severe tubal disease who require in-vitro fertilization (IVF) treatment. Data on the short- and long-term implications of having only one ovary are scarce, and patients in this situation are naturally concerned. This article reviews the effect of possessing a single ovary on the fertility potential and ovarian reserve of these women and their performance in assisted reproduction treatment.