This ethnographic study explores the development and validation of a mental health self-assessment tool tailored for Senegalese adolescents living in Nigeria. A mixed-methods approach was employed, including focus groups with Senegalese adolescents in Nigeria, expert consultations, and a pilot study to refine the self-assessment tool. Ethnographic interviews were conducted to gather detailed insights into cultural contexts and mental health perceptions. The analysis revealed significant cross-cultural differences in how Senegalese adolescents perceive their own mental health status compared to other demographic groups in Nigeria. A preliminary version of the self-assessment tool showed strong internal consistency, but further validation is required to meet psychometric standards across different contexts. This study contributes by providing a culturally tailored mental health assessment tool for Senegalese adolescents living in Nigeria, offering insights into their unique experiences and challenges. Future work will focus on comprehensive validation and wider dissemination of the tool. The developed self-assessment tool should be further validated using larger sample sizes from diverse contexts to ensure its broad applicability. Recommendations for future research include exploring additional cultural dimensions that might impact mental health perceptions.