Over the past few decades, vitamin D was proposed to be highly influential on female fertility and reproductive health. Its role was extensively studied and evaluated specifically in females with polycystic ovarian syndrome. Objectives: the aim of this research was to study the correlation between vitamin D and fertility in general, and in polycystic ovarian syndrome-associated infertility in particular. Methods: we searched Cochrane Library and PubMed for articles addressing the impact and role of vitamin D in fertility issues in females with polycystic ovary disease. Specifically-related topics were carefully reviewed and analyzed to summarize their conclusive results. Results and Discussion: Vitamin D was lower in females with PCOS and vitamin D administration had increased its level, improved metabolic disturbance and shortened inter-menstrual intervals in those patients. Patients with high vitamin D levels had a better success rate of invitro fertilization. However, it did not affect the time to pregnancy in PCOS women. Conclusion: Vitamin D is beneficial for improving metabolic as well as reproductive functions in women with PCOS. It is also essential for successful in-vitro fertilization, and it is probably protective against endometriosis. However, results from different studies are contradictory, and still there is no solid evidence that there is a cause-effect relationship between vitamin D and fertility.