AIM: This study evaluates the clinical effects of a ketogenic diet (KD) versus a traditional comprehensive intervention, including lifestyle changes and oral contraceptives, in overweight or obese polycystic ovary syndrome (PCOS) patients. METHODS: A retrospective analysis of 70 overweight/obese PCOS patients (body mass index [BMI] ≥24 kg/m2) treated between December 2022 and December 2023 was conducted. The patients were categorized into two groups based on their past treatment modality: Group 1 received a KD treatment (N = 35), and Group 2 underwent comprehensive intervention (N = 35), with both treatments lasting 3 months. Changes in body weight, BMI, sex hormone levels, glucose-lipid metabolism indicators, and liver and kidney function were compared. RESULTS: Both groups experienced significant reductions in body weight and BMI after treatment (p < 0.05), with the KD group showing a greater reduction (p < 0.05). luteinizing hormone (LH), LH/follicle-stimulating hormone (FSH), and total testosterone (TT) levels decreased significantly in both groups (p < 0.05). The KD treatment led to significant reductions in fasting blood glucose (FBG), fasting insulin (FINS), homeostasis model assessment of insulin resistance (HOMA-IR), triglyceride (TG), alanine aminotransferase (ALT), and aspartate aminotransferase (AST) (p < 0.05), while the comprehensive intervention resulted in decreased FBG and ALT, and increased high-density lipoprotein-cholesterol (HDL-c) (p < 0.05). Additionally, the KD group had a greater reduction in FBG, and showed decreases in TG and AST, which remained unchanged in the comprehensive intervention group (p < 0.05). CONCLUSION: The short-term KD treatment provides significant weight loss and effectively improves hormone regulation and glucose-lipid metabolism in overweight or obese PCOS patients, offering a valuable therapeutic option for managing the condition.