Background: A high prevalence of low back pain has persisted over the years despite extensive primary prevention initiatives among nurses' aides. Many single-faceted interventions addressing just one aspect of low back pain have been carried out at workplaces, but with low success rate. This may be due to the multi-factorial origin of low back pain. Participatory ergonomics, cognitive behavioral training and physical training have previously shown promising effects on prevention and rehabilitation of low back pain. Therefore, the main aim of this study is to examine whether a multi-faceted workplace intervention consisting of participatory ergonomics, physical training and cognitive behavioral training can prevent low back pain and its consequences among nurses' aides. External resources for the participating workplace and a strong commitment from the management and the organization support the intervention. Methods/design. To overcome implementation barriers within usual randomized controlled trial designed workplace interventions, this study uses a stepped-wedge cluster-randomized controlled trial design with 4 groups. The intervention is delivered to the groups at random along four successive time periods three months apart. The intervention lasts three months and integrates participatory ergonomics, physical training and cognitive behavioral training tailored to the target group. Local physiotherapists and occupational therapists conduct the intervention after having received standardized training. Primary outcomes are low back pain and its consequences measured monthly by text messages up to three months after initiation of the intervention. Discussion. Intervention effectiveness trials for preventing low back pain and its consequences in workplaces with physically demanding work are few, primarily single-faceted, with strict adherence to a traditional randomized controlled trial design that may hamper implementation and compliance, and have mostly been unsuccessful. By using a stepped wedge design, and obtain high management commitment and support we intend to improve implementation and aim to establish the effectiveness of a multi-faceted intervention to prevent low back pain. This study will potentially provide knowledge of prevention of low back pain and its consequences among nurses' aides. Results are expected to be published in 2015-2016. Trial registration. The study is registered as ISRCTN78113519.