Our objective was to identify and describe the major dietary patterns in the Mexican adult population and their association with being overweight or obese. Dietary intake was evaluated by a FFQ that was completed by 15,890 Mexican adults who participated in the National Health and Nutrition Survey 2006. Dietary patterns were generated by cluster analysis based on the percent contribution to total energy intake from 30 food groups. We identified 3 major dietary patterns: refined foods and sweets (RS), traditional (T), and diverse (D). The T pattern was characterized by low dietary diversity, with maize and maize foods accounting for ~47% of energy intake. This pattern had the lowest contribution of most food groups, with the exception of beans (~4.0%). The RS pattern had the highest contribution of alcohol (9.4%), soft drinks (9.4%), white bread (7.7%), fast food, sweets, and snacks. The D pattern had the lowest contribution of maize (15.5%) and the highest contribution of whole-fat dairy (8.0%), rice and pasta, meat, poultry, eggs, saturated fat, fruits, and vegetables. After adjusting for age, gender, physical activity, socioeconomic status, area, and region, the RS and D dietary patterns were associated with 14 and 17% increased risk of being overweight (P < 0.01) and 20% increased risk of being obese, respectively, compared with the T dietary pattern (P < 0.001). These findings support an association of dietary patterns with being overweight or obese in a nationally representative sample of Mexican adults.