The study examined the influence of parenting styles on social adjustment and academic achievement of adolescents in selected secondary schools in Ogun Waterside Local Government Area of Ogun State. Two hundred and forty secondary school students participated in the study. The sample of students was selected from eight secondary schools in Ogun Waterside Local Government Area of Ogun State. Descriptive survey design was used to execute the study. Data were collected through questionnaires and achievement test. The data were analysed using analysis of variance (ANOVA). The study showed that there is significant difference in social adjustment of adolescents from autocratic, democratic and permissive parenting homes. It revealed that adolescents from democratic homes adjust better in social situations than their counterparts from autocratic and permissive homes. The study also showed significant differences in academic achievement of adolescents from autocratic, democratic and permissive parenting homes. It revealed that democratic style of parenting influence academic performance more positively better than autocratic and permissive parenting style.