Brand is one of the most important parts of businesses and many elements are brought together to create a brand. In order for customers to prefer brands, businesses need to consider both customer general and specific expectations, focus on the right points and offer the most appropriate solution to customers because customers consider many factors when making their brand choices. The purpose of this study is to determine which areas the companies operating in the telecommunications sector should focus on according to customer expectations and criteria for brand preference by using the Fuzzy Cognitive Mapping (FCM) method. Customer expectations and criteria are obtained as a result of literature research. After the data are prepared, the most effective criteria are determined with the FCM method. In this study, it is determined that which areas the companies operating in the telecommunications sector should focus on according to customer expectations and criteria. FCM is very useful to decide in complex situations like this. The greatest limitation of this study is determining the customer criteria for brand preference. This study shows that FCM can be very useful to determine the most crucial customer expectations for telecommunications sector. In addition, FCM can be used in other sectors where customer expectations are very important and decisive, to prioritize customer brand preference criteria and to guide businesses.