Cognitive Behavioural Therapy (CBT) has been established as an effective intervention for Post-Traumatic Stress Disorder (PTSD). However, its application in urban slums of Nairobi presents unique challenges and opportunities. A mixed-methods approach was employed, including pre- and post-CBT assessments using standardised tools, alongside qualitative interviews to capture participant experiences and perceptions. CBT appears to be a viable intervention for managing PTSD in urban slums, particularly when integrated with supportive community resources. Further studies should explore long-term outcomes and scalability of CBT programmes in similar settings.