This study was designed to compare general characteristics and dietary habits between volunteers for a nutrition survey and non-volunteers using a questionnaire. Volunteers were recruited by advertising on the homepage of a university to assess nutritional status by examining dietary intake for three days and blood analysis. Non-volunteers were selected from some classes not related to nutrition. There were no significant differences in sex, monthly allowances, eating-out cost, drinking and exercise between the two groups, while the proportion of self-boarding was higher in the volunteer group than in the non-volunteer group, and smoking rate of volunteers was approximately 2.4 times lower than that of non-volunteers. Volunteers were less concerned about their diet than non-volunteers. No significant differences in concern about health, considering factors in their diet, self-evaluation of their diet, learning experience about nutrition, and vitamin/mineral supplement use were observed. The frequency and the place of eating-out for dinner were significantly different between the two groups. More proportions of volunteers tended to eat regularly and eat breakfast. Volunteers consumed seaweeds more frequently, and milk, fruits and fast foods less frequently than non-volunteers. Our results indicate that some characteristics and dietary habits of volunteers are different from those of non-volunteers. However, we could not show that volunteers were more interested in their diet and had desirable dietary habits than non-volunteers. Further research on the characteristics of volunteers who participate in nutrition survey may be helpful to interpret and generalize the survey results.