Action research, which combines the generation and testing of theory with social system change, demands multiple sources of knowledge about the research setting and encourages the integration of data collection techniques. This article describes the implementation of a longitudinal multi-methodological research and intervention project aimed both at examining the relationship between occupational stress and psychosocial moderating factors (e.g., social support, participation, and influence over decision-making) and health outcomes; and reducing work stress and improving employee health. Combining qualitative and quantitative research techniques such as semi-structured individual and focus group interviews, field notes and survey data increases confidence in research findings and strengthens the process and outcomes of needs assessment, program planning, implementation, and evaluation. Specific examples are provided that illustrate the usefulness of this approach in identifying and understanding problem areas and in developing and evaluating appropriate health education interventions.