Objective To explore the consistency of the Patient-generated Subjective Global Assessment (PG-SGA) and Nutritional Risk Screening-2002 (NRS-2002) for nutritional evaluation of patients with gynecologic malignancy and their predictive effect on the length of hospital stay (LOS). Methods We recruited 147 hospitalized patients with gynecologic malignancy from Nanfang Hospital in 2017. Their nutritional status was assessed using the PG-SGA and NRS-2002. The consistency between the two assessments was compared via the Kappa test. The relationship between malnutrition and LOS was analyzed using crosstabs and Spearman\'s correlation. Results The PG-SGA demonstrated that 66.7％ and 54.4％ of patients scoring ≥ 2 and ≥ 4 were malnourished, respectively. Furthermore, the NRS-2002 indicated that 55.8％ of patients were at nutritional risk. Patients with ovarian cancer had a relatively high incidence of malnutrition. However, this was only significant for patients who scored ≥ 4 in the PG-SGA (P = 0.001 and P = 0.019 for endometrial carcinoma and cervical cancer, respectively). The PG-SGA and NRS-2002 showed good consistency in evaluating the nutritional status of patients with gynecologic malignancy (0.689, 0.643 for PG-SGA score ≥ 2, score ≥ 4 and NRS-2002, respectively). Both the scores of PG-SGA and NRS-2002 were positively correlated with LOS. Furthermore, prolonged LOS was higher in patients with malnutrition than in those with adequate nutrition. Conclusion The PG-SGA and NRS-2002 shared a good consistency in evaluating the nutritional status of patients with gynecologic malignancy. Both assessments could be used as predictors of LOS.