According to attachment theory, internal working models of attachment affect the way in which social and emotional information is processed. The current study examined this theoretical claim by investigating the association between attachment security and attention to facial emotional expressions in 5-year-old children. Attachment security was assessed on a representational level using an Attachment Story Completion Task. Children's attention to facial emotional expressions was measured during an eye-tracking task. Gaze data (fixation duration) were collected during the presentation of pictures displaying five different facial emotional expressions (neutral, angry, fearful, sad, and happy) of unfamiliar persons. Moreover, the Emotionality-Activity-Sociability Temperament Inventory was used to control for children's temperament and was filled out by children's mothers. Regression analyses revealed that attachment security was a significant predictor of children's attention to neutral and sad expressions while controlling for age, gender, and temperament. Moreover, a t-test revealed that securely attached children looked longer at the fearful expression than insecurely attached children. These findings provide direct evidence that even on a basic perceptional level attachment security is a predictor of children's emotional information processing. Statement of contribution What is already known on this subject? Attachment representations substantially affect the way in which emotional information is processed. Insecure attachment representations are negatively related to children's attention to emotional stimuli. What does this study add? Eye-tracking technology was used to measure children's visual attention to facial emotional expressions. Secure attachment was related to prolonged visual attention to neutral and negative facial emotional expressions. Attachment security influences children's emotional information processing even on a basic perceptual level.