The study assesses the factor structure, reliability, and construct validity of three widely used scales—the Patient Health Questionnaire 9 (PHQ-9), Generalized Anxiety Disorder 7 (GAD-7), and the Primary Care PTSD Screen for DSM-5 (PC-PTSD-5)—among 230 South African adolescent girls aged 15-19 years enrolled in a longitudinal HIV prevention intervention. The research highlights the lack of psychometric evaluations of these scales in Global South contexts, especially among adolescents, and aims to fill this gap by examining these tools' applicability and effectiveness in a South African setting.