Exposure to food service establishments is considered to encourage consumption and contribute to poorer diet quality, and hence adverse health profiles. However, empirical verification of these links remains rare, particularly in young adults and non-Western populations. The objective of this cross-sectional study was to test the hypothesis that neighborhood restaurant availability and frequency of eating out are associated with unfavorable patterns of dietary intake and thus possibly higher body mass index (BMI) and waist circumference in young Japanese women. The subjects were 989 female Japanese dietetic students 18 to 22 y of age. Dietary intake and frequency of eating out (i.e., consumption of commercially prepared meals) during the preceding month were assessed using a comprehensive, self-administered diet history questionnaire. Neighborhood restaurant availability was defined as the number of restaurants within a 0.5-mile (0.8-km) radius of residence (i.e., full-service restaurants, limited-service restaurants, and cafeterias). Increasing frequency of eating out was associated with higher intake of meat, confectionery and bread, and dietary fat, lower intake of fruit and vegetables, rice, and dietary fiber, and higher dietary energy density. However, neighborhood restaurant availability was not associated with either the frequency of eating out or any of the dietary variables examined. Further, frequency of eating out and neighborhood restaurant availability were not associated with BMI or waist circumference. In conclusion, although frequency of eating out was positively associated with unfavorable dietary intake patterns in a group of young Japanese women, neighborhood restaurant availability was not associated with frequency of eating out or dietary intake.