Introduction In patients with advanced ovarian cancer, malnutrition is a significant concern. It might be associated with poor treatment outcomes. This study aims to determine the prevalence of malnutrition in advanced ovarian cancer patients and investigate the effect of malnutrition on surgical and oncological outcomes for the disease.

Methods 290 advanced ovarian cancer patients (FIGO stage 3–4) who were never diagnosed as ‘malnutrition’ for another reason were enrolled in the study. We determined malnutrition status using the geriatric nutritional risk index (GNRI). Information derived from medical records was gathered, including BMI, treatment complications, and length of hospital stay.

Results This study showed 137 of 290 patients (47.2%) have malnutrition. Anemia and CKD were presented concomitant with malnutrition. Malnutrition impacts both surgical and oncological outcomes, including the percentage of optimal surgeries (35.8% in the malnutrition group and 62.7% in the well-nourished group) and the length of hospital stays (malnourished patients stayed longer than the average by three days). It was also found that well-nourished patients had a higher overall survival rate of more than 12.97 months than those with malnutrition patients.

Conclusion/Implications Advanced ovarian cancer patients frequently had malnutrition. Malnutrition reduces optimal surgery rate, may lengthen hospital stays, and may reduce overall survival rates.