The aim of this present study was to examine the relationship of parental styles and effects of these parental styles on personality functioning dimensions (cooperativeness & effectiveness) of students at secondary level. The focus of this study was on four parental styles (permissive, uninvolved, authoritarian and authoritative).The objective of the study was to find out relationship between parental styles and personality functioning dimensions of students at secondary level. Parental styles have been identified as a contributing factor in child personality. In Pakistan very few researchers have focused on personality functioning dimensions (cooperativeness and effectiveness). The population of this study was including all the secondary level students of government schools and students' parents from Faisalabad city. The sample of this study comprised of two hundred male students and two hundred female students and their parents. Two research instruments were developed by researcher. One questionnaire was for students which contained thirty one statements and the one was for student's parents which contained thirty statements. The researcher translated these two instruments into Urdu and used them after pilot testing. Sixteen null hypotheses were tested to see the relationship between parental styles and personality functioning dimensions (effectiveness and cooperativeness) of students at secondary level. Data was analyzed by using Pearson Correlation. After analysis it was found that mostly parents has authoritarian parental style. It was concluded that all parental styles have significant effect on child's personality. It was found that uninvolved parents are very few. It was observed at the offspring's of uninvolved parents are negative and confused individuals. Along with it results show that the children of authoritative parents are more effective and cooperative in their dealings.