Objective: To evaluate the association between migraine and the risk of becoming overweight and obese. Background Cross-sectional studies have suggested an association between migraine and increased relative body weight. However, the direction of the association remains unclear. Design/Methods: Prospective cohort study among 19,162 participants in the Women9s Health Study aged 45 years and older and who had a body mass index (BMI) Results: 3,483 (18.2%) reported any migraine history. After a total of 12.9 years of follow-up, 7,916 women became overweight and 730 obese. While women who reported any history of migraine had a slightly increased hazard ratio (95% confidence interval) of 1.12 (1.06, 1.19) for becoming overweight, they were not at increased risk for becoming obese (HR: 1.00, 95% CI: 0.83, 1.19). These associations remained stable after censoring women for incident chronic diseases (cancer, CVD). The lack of association was not modified by migraine aura status or by migraine frequency. Multivariable-adjusted mean weight chance from baseline until the end of study was +4.7kg for migraineurs and +4.4kg for participants without migraine (P=0.02). Conclusions: Results of the large prospective study of middle-aged women do not indicate a consistent association between migraine and incident overweight, obesity, or relevant weight gain. Our data do not support that migraine should be considered a risk factor for obesity. Supported by: The Women9s Health Study is supported by grants from the National Heart, Lung, and Blood Institute (HL-043851, HL-080467, HL-099355), and the National Cancer Institute (CA-47988). Disclosure: Dr. Winter has nothing to disclose. Dr. Buring has nothing to disclose. Dr. Kurth has received personal compensation for activities with Merck & Co. & MAP Pharmaceuticals as a speaker and participant on an expert panel. Dr. Kurth has received personal compensation in an editorial capacity for the British Medical Journal.