Background: According to an Anglo-Saxon study, in breast cancer survivors, there is a high prevalence of impaired fasting glucose. Our aim was to assess the impaired fasting glucose occurring in Mexican woman survivors of breast cancer. Materials and Methods: At a general hospital in Mexico City, women with breast cancer with a surviving ≥2 years, without type 2 diabetes mellitus, were studied. The analysis included demographic and anthropometric features, time of surviving, and blood levels of lipids and glucose. Results: The sample was 119 women. Impaired fasting glucose happened in 53 (44.5%). In those with normal weight (n = 28), impaired fasting glucose occurred in 9 (32.1%); however, in overweight participants (n = 48), it developed in 22 (45.8%) and in obese participants (n = 43) in 22 (51.1%). Conclusion: Impaired fasting glucose is usual in Mexican breast cancer survivors. It is more in obese and overweight women compared to normal weight.