Following the environmental detection of vaccine-derived poliovirus type 2 (cVDPV2) in Mwanza City, Tanzania, a social diagnostic study was conducted in April 2025 to assess polio vaccination coverage, community knowledge, attitudes, and practices. This study, a collaboration between the Ministry of Health, UNICEF, Tanzania Inter-faith Partnership (TIP), and Muhimbili University of Health and Allied Sciences (MUHAS), aimed to identify factors contributing to missed vaccinations and inform targeted Risk Communication and Community Engagement (RCCE) interventions. The findings reveal high vaccination coverage alongside critical gaps in knowledge and hygiene practices, highlighting the need for integrated strategies to achieve lasting polio eradication.