The purpose of this study, as a national research, was to investigate the effects of the parents’ relational and supervision behavior on the academic achievement and social adjustment of their university student chil-dren.2636 individuals, including 1318 undergraduate, unmarried students from Shahid Beheshti, Tabriz, Isfahan, Gilan and ShahreKord universities (421 underachieved, 411 with good achievement who were matched with the underachieved group, 237 maladjusted and 245 with no problem in their adjustment and/or achievement who were matched with the maladjusted group), and 1318 responded pa-rents (mother or father) were selected through systemic sampling method. Both members of the family (student and his/her parent) separately completed a questionnaire about quality and quantity of the students’ relationships with their family and also the parents’ supervision beliefs and behavior. The results revealed that the maladjusted and underachieved groups have significantly lower mean scores on the “Quantity of Relationships”, “Quality of relationships”, Supervision Behavior”, and “Need for Supervision” scales, all of them as viewed by both the young adult children and parents, than the good-achievement and no-problem groups. The role of the quality of parent-child relationships and amount of parental control on the mental health, academic achievement and adjustment of the university students via increasing their motivations as well as their self-efficacy is discussed.