Theoretical speculations and empirical data on the relation between attachment and moral reasoning are presented. An autonomous attachment representation was hypothesized to be an important personality dimension facilitating higher levels of moral (Type B) reasoning in adolescence. A sample of 47 U.S. college students (mean age 19.5 years) completed the Adult Attachment Interview (Main & Goldwyn, 1985-1993) and the Sociomoral Reflection Measure-Short Form (Gibbs, Basinger, & Fuller, 1992). Although the overall score for sociomoral reflection was not associated with attachment representation, moral Type B reasoning was more prevalent in respondents with an autonomous attachment representation; thus, autonomous attachment may be at the core of mature moral reasoning.