A key barrier to epidemiological research on child behaviour problems in developing countries is the lack of culturally relevant, internationally recognized psychometric instruments. This paper proposes a model for the qualitative adaptation of psychometric instruments in developing-country settings and presents a case study of the adaptation of 3 internationally recognized instruments in Pakistan the Child Behavior Checklist, the Youth Self-Report and the Teacher's Report Form. This model encompassed a systematic procedure with 6 distinct phases to minimize bias and ensure equivalence with the original instruments selection, deliberation, alteration, feasibility, testing and formal approval. The process was conducted in collaboration with the instruments' developer. A multidisciplinary working group of experts identified equivalence issues and suggested modifications. Focus group discussions with informants highlighted comprehension issues. Subsequently modified instruments were thoroughly tested. Finally, the instruments' developer approval further validated the qualitative adaptation. The study proposes a rigorous and systematic model to effectively achieve cultural adaptation of psychometric instruments.