Background: Perinatal depression is defined as a non-psychotic depressive episode occurring during pregnancy or during the first year following childbirth. This depressive disorder is highly prevalent among teenage women but there is a lack of data in low- and middle-income countries. The objective of this study was to provide baseline data on the sociodemographic characteristics of pregnant teenagers or teenage mothers in an urban zone in Yaoundé, Cameroon. Risk factors were assessed, and prevalence of depressive disorders was determined. Methods: Women aged 20 years old or less in the perinatal period were invited to participate in the study. A total of 1344 women participated in the four-stage data collection process involving a questionnaire including questions on sociodemographic background, an assessment of their risk of perinatal depression using the EPDS questionnaire (Edinburgh Postnatal Depression Scale), a clinical interview based on the DSM 5 (Diagnostic and Statistical Manual of Mental Disorders), and a final section focusing on risk factors of perinatal depression. Results: The EPDS score was obtained for 1307 women. The prevalence of depressive disorder symptoms among teenage or young pregnant women is estimated to be 70.0%. This risk is significantly increased by different factors including unintended or unplanned pregnancy (aOR: 1.33, 1.14–1.56 CI95%), being separated or single (aOR: 1.34, 1.12–1.60 CI95%), experiencing depression and anxiety before childbirth (aOR: 1.50, 1.02–2.27 CI95%), abortion experience (aOR: 2.60, 1.03–7.14 CI95%) and domestic violence (aOR: 1.76, 1.12–2.83 CI95%). Conclusion: The results of this study reveal a high prevalence of depressive disorder symptoms within the study population. These findings highlight the need to develop maternal care programs to support both mothers and their infants. of perinatal depression. Results: The EPDS score was obtained for 1307 women. The prevalence of depressive disorder symptoms among teenage or young pregnant women is estimated to be 70.0%. This risk is significantly increased by different factors including unintended or unplanned pregnancy (aOR: 1.33, 1.14–1.56 CI95%), being separated or single (aOR: 1.34, 1.12–1.60 CI95%), experiencing depression and anxiety before childbirth (aOR: 1.50, 1.02–2.27 CI95%), abortion experience (aOR: 2.60, 1.03–7.14 CI95%) and domestic violence (aOR: 1.76, 1.12–2.83 CI95%). Conclusion: The results of this study reveal a high prevalence of depressive disorder symptoms within the study population. These findings highlight the need to develop maternal care programs to support both mothers and their infants.