Companies, striving towards an effective and systematic integration of a strategic sustainability perspective in product innovation, need to treat the implementation of necessary processes and tools, as well as their continuous improvement, as a project in itself. An efficient way to measure the current sustainability implementation level in the organization, as well as guidance for progression, is required. To meet this need, a novel self-assessment was developed, which provides companies with a tool to assess and visualize their current capabilities in relation to key elements for successful sustainability integration in the product innovation process. It includes a scale of different sustainability implementation levels to support building a roadmap for systematic implementation, and to measure progress over time. This research is based on results from previous descriptive work within the area of sustainable product development and learning from applying strategic and tactical assessment tools for eco-design and sustainability maturity. Besides the contribution to practice, this study also contributes to knowledge by specifying detailed aspects for each key element that must be considered to guide sustainability integration. Also, insights from applying different existing tools in real cases are provided. The newly-developed self-assessment method was applied and validated at two case companies. Independent and continuous use of it by the companies beyond this particular study indicate the practical value of the method.