Objective: To identify the preoperative nutritional status of women with gynecologic or breast cancer, in correlation with disease site and staging as well as previous treatments. Subjects and methods: A cross-sectional study of 250 women evaluated by Body Mass Index (BMI) and Subjective Global Assessment (SGA). For data analysis, the chisquare test was applied. Results: Breast cancer was the most frequent cancer, predominating in 56.2%. The median age of the patients was 52 years. In about 57% of these women, the tumor was restricted to clinical stages 0, I and II and 77% of the women had not undergone any other oncologic treatment prior to surgery. Subjective Global Assessment detected 76% of nourished women and 24% undernourished women, while Body Mass Index identified 34% of nourished women, 3.6% undernourished women and 62.4% overweight/obese women. A low level of diagnostic agreement between normal nutrition and malnutrition by both methods was observed (63.8%; kappa (95% CI) = 0.0884 (-0.07-0.24). No correlation between nutritional evaluation and previous treatment and disease staging was observed. Concerning anatomic site, it was subjectively observed that women with cancer of the uterine corpus were more malnourished than the rest (p = 0.02). Conclusions: The findings suggest that a more careful evaluation should be employed to identify preoperative nutritional status in women with gynecologic or breast cancer.