Background Parent-to-child maltreatment has been demonstrated to drastically affect a child’s mental well-being and plays a significant role in developing depressive symptoms. However, little is established about the effect of frequency of parent-to-child maltreatment on the development of depressive symptoms among Pakistani adolescents. Methods A longitudinal prospective study was conducted, from 2015 to 2017, with 800 adolescents aged 11–17 years old recruited from 32 systematically selected urban and peri-urban areas of Karachi. First, these adolescents were screened for parent-to-child maltreatment in 2015 in a cross-sectional survey. Children with diagnosed psychiatric conditions were excluded from the study. In the second phase, these individuals were followed for 2 years to investigate the symptoms of depressive disorder using a validated tool, “CES-D (Center for Epidemiological Studies) Depression scale.” The Cox proportional algorithm was used to examine the relationship between the frequency of parent-to-child maltreatment and depressive symptoms. Results Approximately 11% of frequently, 9% of occasionally parent-to-child, and 7%of negligibly maltreated adolescents reported depressive symptoms over 2 years. The other significant predictors of depressive symptoms were no formal education of the child (RR: 3.15, 95% CI: 1.35–7.34), presence of stressful home environment (RR: 2.19, 95% CI: 1.22–3.94), and having both uneducated parents (RR: 1.70, 95% CI: 0.90–3.21). The frequently maltreated females were found to have 4 times the higher risk compared to rarely maltreated males. In addition, frequently maltreated males were twice likely to develop depressive symptoms. Conclusion The results suggested that frequent parent-to-child maltreatment occurring during childhood leads to the development of depressive symptoms later in the adolescence period. Thus, there is a dire need for interventions to raise awareness among the society on the issue of parent-to-child mistreatment to minimize later mental health consequences.