Studies have reported the rising spate of antisocial activities among secondary school students. But, there are questions about why, and what are the root causes of these antisocial activities among student, which is yet to be answered? Among the youths, family background provides the basic foundation and the most valuable and indispensable school of socialization. In a typical African family setting, the family is the most basic unit of life which represents the miniature life of the entire people in a community. The aim of this study was to determine the influence of family background on adolescent social adjustment in Southern senatorial district of Cross River State, Nigeria. Four research hypotheses were formulated for this study and tested at .05 level of significance with 348 degrees of freedom. A well validated 23-item questionnaire was used to collect the required data. The data collected was tested using the independent t-test analysis for the hypotheses. From the analysis, the following findings were made among others: there is a significant influence of family type on student's social development (P > 0.05). Family structure significantly influence student's social adjustment. The study will be of great benefit to the parents, students, teachers, educational planners, policy makers, counselors, psychologists, religious bodies and future researchers. This is so because the findings reveals the actual causes of and remedy to antisocial behaviour among students. The parents would be informed of the role of family background in the socialization of adolescents.