Epidemiological studies have shown that patient transfer is a risk factor for back pain, back injuries and long term sickness absence, whereas consistent use of assistive devices during patient transfer is associated with reduced risk of back injury. In consequence, Danish hospitals have made great efforts to increase knowledge, availability and use of assistive devices to reduce work-related physical strain due to patient transfer. Yet, a recent survey among more than 300 nurses and nurses' aides showed that two thirds rarely uses assistive devices during patient transfer. Thus it seems relevant to investigate barriers, opportunities and practical solutions for increasing use of assistive devices among healthcare workers. The purpose of this study is to evaluate a participatory organizational intervention for improved use of assistive devices during patient transfer.