Social networking sites have started to become one of the most frequently used online communication types in the world. It is reported that one of the commonly used social networking sites is Facebook. Since Facebook use is new yet, it can be stated that researches on the Facebook addiction are at the beginning level. For this reason, determining factors leading to the Facebook addiction has gained importance. In this context, in this study, relationships between attachment styles and the Facebook addiction were examined. The participants of the study were 322 university students [145[subscript (45%)] male, 177[subscript (55%)] female, M[subscript age] = 20.61 years, SD = 1.82]. In the study, the Personal Information Form, the Relationship Scales Questionnaire and the Facebook Addiction Scale were administered. The relationships between attachment styles and the Facebook addiction were calculated via using the Pearson correlation analysis. The Pearson correlation analysis results indicated that the Facebook addiction was negatively related with the secure and dismissing attachment style and positively related with the preoccupied attachment style. No relationship was found between the fearful attachment style and the Facebook addiction. If the attachment styles predicted the Facebook addiction was examined via using the stepwise regression analysis. The research findings indicated that the secure and dismissing attachment style negatively predicted and the preoccupied attachment style positively predicted the Facebook addiction. However, it was determined that the fearful attachment style did not predict Facebook addiction. The research findings were discussed under the light of related literature.