The purpose of this study was to examine the effect of childrearing practice on adolescent psychosocial functioning. In order to carry out this study, a sample of 328 of 133 males and 195 female adolescent students were selected randomly from three secondary schools of East Hararghe Zone. Data were collected through self-reporting questionnaire and analyzed using both descriptive and inferential statistical methods such as, frequency, tabulation, mean, standard deviation, range, one sample t-test, Pearson moment correlation, two-way ANOVA and multiple regression. Findings indicate that participants of the study have a reasonably acceptable level of psychosocial functioning and they perceive their parents' childrearing practice is fairly good. There is strong and significant relationship between parental childrearing practice and adolescents' psychosocial functioning. The gender disparity has been observed among the dimensions of child rearing practice on controlling and psychosocial functioning and also among its dimensions on behavior and relationship problems in favor of females. In addition, according to the results of ANOVA, there is psychosocial functioning difference among adolescents with respect to their level of parental childrearing practice. The main effects of gender and level of childrearing practice on psychosocial functioning are significant while together they do not have an interaction effect. Besides, most of the variability in explaining psychosocial functioning which is accounted for 64.4% is explained by parental childrearing practice and its dimension, nurturance, did not seem to explain variability in psychosocial functioning. In the end, recommendations are also made for how to properly address the gaps noted in this research.