The relationship of levels of moral reasoning to behavioral dimensions of juvenile delinquency was investigated, using 162 delinquent boys in a reformatory. After adding biographical data to the Quay Behavioral Classification Instruments, four second-order factors were obtained, interpreted as a social inadequacy, an obstreperousness, a social orientation and an antisocial egocentricity factor. The principled morality score of Rest's Defining Issues Test correlated negatively with a social inadequacy score while a score measuring morality of rules and duty to social order correlated with a score indicating a group inclined social orientation. Unexpectedly delinquents with antisocial egocentristic tendencies did not display lower principled morality scores. Some evidence for the validity of Quay's Inadequacy-immaturity dimension was found_