In the frame of the developed model, this study aims at testing whether the mediation of separation and/or individuation between the relationship of secure parental attachment and his/her personal adjustment for a late adolescent is effective or not in Turkish culture. In this study, the developed model was tested in two stages. The theoretically developed model was tested whether (or not) the relations between the theoretically mentioned structures fit the observed data in first stage. As the model statistically fitted the structural equation model, the model test which was done in second stage. In conclusion, the mediation of separation-individuation between the relationship of secure parental attachment and personal adjustment was accepted. It has shown that the mediation of separation-individuation between the relationship of secure maternal-paternal attachment and personal adjustment was shown to be valid in Turkish culture. Some adjustment problems of students can be prevented through conducting studies to materialize their secure parental attachment and separation-individuation in the frame of the psychological counseling and guidance services that are carried out at universities.