A secondary survey was conducted of 503 customers, to investigate eating out behaviours at five fast food restaurants of Youido apartment compound in Seoul, in April of 1988. The results are summarized as follows: The majority, 84% of customers, were aged 14 to 30, consisting of junior and senior high school children, college students and company employees. In contrast to the previous survey of 1986, in which no elderly customers were found, a small number of elderly customers were observed in this study. The reasons given by customers for patronizing fast food restaurants were the following, from most to least frequent: 'convenient', 'allows for companionship', 'the pleasant place to eat', 'dining equipment and tableware are hygienic', 'to be able to stay as long as I want', and 'foods rapidly served'. Only 24.2% of the customers purchased the fast foods for a full meal, 38.3% purchased the foods for snacking, and others purchased ice cream only or drink only. The majority of the customers ate the purchased foods at the fast food restaurants. However, a limited number of female customers preferred to take the packed fast foods to their homes. Taste preference was a major factor in food selection from available menu items, among the younger customers; whereas customers over 30 years old were concerned with nutritive balance. Fried chicken, pizza, rolled rice with laver, ice cream, and juice were high on the list of liked foods; in contrast, lower preference was for fish burger, doughnut, spaghetti, Chajang noodles and chili beans. The survey discovered that the preference for fried chicken, pizza, and salad had increased compared to the previous survey of 1986. Preference by food nationality was highest for Korean food, then Western food, Chinese food, and Japanese food, in that order. Customers offered suggestions for better fast food service, such as lowering the price; greater variety in the menu; developing fast foods from the traditional Korean foods; and increasing the proportion of vegetables and fruits on the fast food menu. The customers, in particular, emphasized a need for the development of Korean traditional beverage of malt drink and persimmon punch, as well as mungbean pan cakes and sweet- spicy rice noodles (docbokki), as fast foods.