ABSTRACT: Introduction & Objective: Nowadays the extensive changes in lifestyle resulted in an increase in consumption of fast food. This type of food, because of using deep–fat frying, may contain some toxic or unfavorable substances which have adverse effects on consumers’ health. The aim of this study was to determine the peroxide value of edible oils which are used in restaurants and sandwich shops in Yasouj city. Materials & Methods: This descriptive study was carried out on all sandwich shops (n=36) and restaurants (n=12) in Yasuj city in 2006. All samples and questionnaire data in restaurants and sandwich shops were collected at 11:30am and 12:30pm respectively based on a national standard protocol, number 493, by a food expert. The peroxide value was determined based on national standard procedure, number 4179, in a food laboratory and the acceptable limit was defined as 7 meq/kg. Results: Findings of this study showed that in terms of health rules and regulations, at least 50% of oils used in restaurants and 70% in sandwich shops were unfavorable. Peroxide value of 58.3% of oils in restaurants and 97.3% in sandwich shops was greater than the acceptable limit. Conclusion: These findings have shown that the health rules and regulations for the oils are not exercised in Yasouj restaurants and sandwich shops and this can have adverse effects on consumers’ health.