The role of occupational therapy in prevention has received much discussion but relatively little empirical testing and model building. Because of the evidence linking stress and illness, the life stress process has become a popular area of investigation. More importantly, a role strain model can provide a theoretical guide to occupational therapy practice due to the central importance of adaptive behavior and social competence. To illustrate, the maternal stress study is presented as an example of prevention research that examines the relationship between maternal stress and child psychopathology. Risk factors are identified as the first step in reliable case finding and the design of preventive interventions. Such model building can help occupational therapists develop prevention services for vulnerable populations.