The purpose of this article is to demonstrate the application of mixed methods research designs to multiyear programmatic research and development projects whose goals include integration of cultural specificity when generating or translating evidence-based practices. The authors propose a set of five mixed methods designs related to different phases of program development research: (a) formative research, Qual [right arrow]/+ Quan; (b) theory development or modification and testing, Qual [right arrow] Quan [right arrow]/+ Qual [right arrow] Quan...Qual [right arrow] Quan; (c) instrument development and validation, Qual [right arrow] Quan; (d) program development and evaluation, Qual [right arrow]/+ Quan [right arrow]/+ Qual [right arrow]/+ Quan...Qual [right arrow]/+ Quan, or Qual [right arrow][left arrow] Quan; and (e) evaluation research, Qual + Quan. We illustrate the application of these designs to creating and validating ethnographically informed psychological assessment measures and developing and evaluating culturally specific intervention programs within a multiyear research program conducted in the country of Sri Lanka. (Contains 1 figure and 2 tables.)