Objective: Latino day labourers (LDLs) in the USA are at increased risk for non-fatal and fatal occupational injuries, which are compounded by stressors that include wage theft, job insecurity and discrimination. This paper describes the development and refinement of Vales+Tú (You are Worthy of More), an injury prevention programme currently being evaluated as part of a cluster randomised trial in which health promotion is taken directly to the 'corners' (e.g. street corners, home improvement store parking lots, and public parks) where workers gather to seek employment. Design: Vales+Tú comprises two corner-based intervention approaches, group problem-solving (small group discussions) and brief motivational interviewing (one-on-one dialogue), that aim to activate LDL agency to control their safety and that of their peers. Setting: Corners in Houston, Texas, where LDLs seek employment. Method: Intervention Mapping informed the refinement of Vales+Tú for the current trial. We provide a narrative review of the development process based on needs assessment and formative development activities (surveys, focus group discussions and pilot tests). Results: In addition to documenting the need for LDL injury prevention, with 20.2%-41.6% of Houston-based LDLs surveyed between 2013-2014 and 2019 reporting a severe work-related injury in the past year, we describe key facets of the Vales+Tú corner-based intervention approaches -- including their theoretical basis and LDL-centred activities, as well as enhancements made informed by formative evaluation. Conclusion: The community-engaged development process of Vales+Tú resulted in two practical intervention approaches that can be adopted by worker centres and other organisations to promote LDL worker safety.