Background: Premature ovarian failure (PMOF) associated with increased risk of the general and mental health of the affected women, however, lower fertility or even infertility are the most disturbing symptoms to every woman with PMOF. Therefore, this study was conducted to assess the prevalence of PMOF among infertile women as this may reflect the real magnitude of the problem in the whole population. Methodology: women aged 40 years or less with infertility and menstrual irregularity (oligomenorrhea or amenorrhea) and with an elevated FSH level on two occasions more than 4 weeks apart were recruited for this study. The participants were attending Albayda Fertility Centre a public centre in Libya, between August 2013 and January 2020. The results: the recorded prevalence of PMOF among infertile subjects in this study was 2.8%. 34% of the affected women were aged 35 years and below. Only 2 (3.45%) of them got spontaneous pregnant, but none ended in live-birth. The median age at presentation was 36 years. The median infertility duration was 4.5 years and the median duration of menstrual irregularity was 7 years. The menstrual irregularity predated infertility by a median of 2.5 years. Conclusion: the prevalence of PMOF in this study was 2.8% indicating a higher prevalence of PMOF among infertile women than previously reported prevalence in the general population. This study also confirms the low reproductive potential of these women.