As part of a larger research project focusing on attachment conducted at Lund University, the links between attachment and aspects of the relationship with a best friend in middle childhood were examined. 66 children ages 10 to 11 years participated, 28 boys and 38 girls. Attachment and three aspects of a best friendship was measured using the Friends and Family interview (FFI), a semi-structured attachment interview addressing children’s mental representations of attachment and parental availability as well as children’s perceptions of relationships with close friends. The Secure Base Script Test (SBST), a narrative-based measure of secure base scripts in middle childhood, was included as a second measure of attachment. Results show associations between coherence in the children’s attachment representation (FFI) and quality in the friendship as well as diversity of feeling, but not with frequency of contact with friend. No association between secure base scriptedness and the three aspects of friendship was found. Minor gender differences were found in the quality of best friendship. The results imply that not only quality, but also diversity of feeling in best friendship, is associated with attachment in middle childhood.