Satisfaction is the sum of the advantages of a product or service, and providing a special experience to customers is crucial for success in the market. If the customer considers the service or product better compared to the others offered, he will be very satisfied and in most cases will repeat his purchase and recommend the product to others. However, due to the increasing number of competitors, it is increasingly difficult to win over customers and make them satisfied. Satisfaction can be seen as the main indicator of business success, therefore it is a frequent subject of numerous researches. It can change over a period of time, and most of them relate to the comparison of unmet expectations and performance. In this research, we investigate the satisfaction of fast food customers in the area of the city of Zagreb. The focus is the research of several factors on the satisfaction of fast food customers, namely the physical environment, price, product quality, service quality and promotion. A total of 102 respondents participated in the survey, and satisfaction was examined using a survey questionnaire on a purposeful (opportunity) sample. According to the research results, customers of fast food restaurant chains in Zagreb are satisfied. Customers singled out the cleanliness of the restaurant, the warmth of the food served, the price-quality ratio, the excellent taste, the comfort of the place for a meal and the responsibility of the waiter as the most important. There are deviations between satisfaction and the importance of the mentioned claims, where the biggest deviation is present in the satisfaction and importance of a good price-quality ratio. Restaurants should maintain the high quality of their products and services in order to maintain high customer satisfaction and maintain a competitive advantage over other restaurants.