Objective: To determine the association between measures of overall diet quality (dietary indices/patterns) and risk of multiple sclerosis (MS). Methods: Over 185,000 women in the Nurses’ Health Study (NHS) and Nurses’ Health Study II (NHSII) completed semiquantitative food frequency questionnaires every 4 years. There were 480 MS incident cases. Diet quality was assessed using the Alternative Healthy Eating Index-2010 (AHEI-2010), Alternate Mediterranean Diet (aMED) index, and Dietary Approaches to Stop Hypertension (DASH) index. Principal component analysis was used to determine major dietary patterns. We calculated the hazard ratio (HR) of MS with Cox multivariate models adjusted for age, latitude of residence at age 15, body mass index at age 18, supplemental vitamin D intake, and cigarette smoking. Results: None of the dietary indices, AHEI-2010, aMED, or DASH, at baseline was statistically significantly related to the risk of MS. The principal component analysis identified “Western” and “prudent” dietary patterns, neither of which was associated with MS risk (HR, top vs bottom quintile: Western, 0.81 ( p = 0.31) and prudent, 0.96 ( p = 0.94)). When the analysis was repeated using cumulative average dietary pattern scores, the results were unchanged. Conclusion: There was no evidence of an association between overall diet quality and risk of developing MS among women.