Polycystic ovarian syndrome (PCOS) is a common reproductive and endocrinological disorder that affects a significant percentage of women worldwide. Despite its high prevalence, the possible environmental factors that influence the development of PCOS, especially dietary habits, are still unclear. The aim of this study is to investigate the association between PCOS and junk food consumption among women of childbearing age in Jeddah, Saudi Arabia. A cross-sectional study was conducted from February 2023 to April 2023 in 155 women diagnosed with PCOS according to the Rotterdam criteria. Participants aged 18-47 years and living in Jeddah, Saudi Arabia completed a validated 30-item electronic questionnaire that included sociodemographic information, medical history, PCOS symptoms, and fast food consumption patterns. The study revealed a high prevalence of obesity and overweight among PCOS patients, which was significantly associated with their diets high in carbohydrates, fats, and refined sugars. In addition, weight loss was difficult for these patients, which could be influenced by hormonal imbalances and dietary factors. In particular, fast food consumption showed a significant association with facial acne in PCOS patients, while some participants also experienced excessive hair growth on the face, abdomen, and back, which may be related to excessive fat intake. This study provides evidence to support an association between junk food consumption and the prevalence of PCOS among women of reproductive age in Jeddah, Saudi Arabia. The findings suggest that dietary patterns may influence the development and treatment of PCOS, highlighting the need for lifestyle interventions as part of treatment strategies. Further studies with larger and more diverse populations, as well as longitudinal studies, are warranted to clarify causal relationships and gain a comprehensive understanding of the impact of dietary factors on the development and progression of PCOS. Identifying the potential effects of diet on PCOS can lead to more effective treatments and improve the overall health and well-being of those affected.