Background <p>Cancer care efficiency contributes to overall healthcare systems performance. However, many healthcare systems experience challenges in measuring it effectively. All.Can, a multi-stakeholder organization working to improve cancer care efficiency, has identified eight cancer metrics as a starting point for standardizing efficiency measurement, focussing on timeliness of care, coordination of care and patient-centredness. This study aims to identify barriers and enablers to implementing these metrics globally and to describe the co-development of a guide to support stakeholders in embedding these metrics into healthcare workflows.</p> Methods <p>This qualitative study used a co-development approach in collaboration with the All.Can community. Semi-structured interviews were conducted to identify barriers, enablers and good practices in implementing cancer care efficiency metrics. Data were analysed using a combination of deductive and inductive coding, guided in part by the Implementation in Context (ICON) framework. A qualitative content analysis was conducted to explore the perceived actionability of contextual factors, which informed the development of an Action Guide grounded in health systems research principles. The guide was reviewed by potential end-users and launched in September 2024.</p> Results <p>A total of 40 informants from 21 countries participated in semi-structured interviews. Regulatory influences were most frequently cited as relevant factors for implementing timeliness-of-care metrics. Barriers included fragmented or missing regulations on cancer data collection and limited database interoperability, whilst enablers involved national strategies and standardized care pathways. For coordination-of-care metrics, regulatory issues were again central, notably the lack of regulation defining roles such as oncology nurses and care coordinators. Political influences emerged prominently for patient-reported metrics, including lack of funding and absence of systematic data collection strategies. Advocacy was often seen as a key enabler. These informed the development of an Action Guide, intended to support the implementation of cancer care metrics.</p> Conclusions <p>This study identified contextual barriers and enablers for implementing cancer efficiency metrics and described the co-development of the All.Can Action Guide as a practical tool for policymakers, care providers and advocates. Through mapping priority areas for action, this study may strengthen data-driven decision-making, enhance timeliness and coordination of care, and ultimately improve patient outcomes and experiences worldwide.</p>